Hello @E1cid ,
again, thank you for your help 
I checked your proposal and for sure it worked for the given example.
But in my first post I didn't choose the example right. Indeed there are several Values I'd want to fetch from the HTML.
So here the complete HTML:
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="de">
<head>
<title>STIEBEL ELTRON Reglersteuerung</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta http-equiv="imagetoolbar" content="no" />
<meta name="content-language" content="de" />
<meta name="robots" content="noindex,nofollow" />
<meta name="keywords" content="" />
<meta name="description" content="" />
<link rel="shortcut icon" href="./pics/brlogo.ico">
<!-- does not exist link rel="stylesheet" href="./css/netzwerk.css" type="text/css" media="all" /-->
<link rel="stylesheet" type="text/css" href="./css/slider/ste_slider.css" />
<!-- Blueprint CSS framework -->
<link rel="stylesheet" href="./css/blueprint/screen.css" type="text/css" media="screen, projection" />
<link rel="stylesheet" href="./css/blueprint/print.css" type="text/css" media="print" />
<!--[if lt IE 8]><link rel="stylesheet" href="./css/blueprint/ie.css" type="text/css" media="screen, projection" /><![endif]-->
<link rel="stylesheet" href="./css/layout.css" type="text/css" media="all" />
<link rel="stylesheet" href="./css/sifr.css" type="text/css" media="all" />
<link rel="stylesheet" href="./css/thickbox.css" type="text/css" media="all" />
<link rel="stylesheet" type="text/css" href="./css/jquery.jqplot.min.css" />
<script type="text/javascript" src="./js/jquery.min.js"></script>
<script type="text/javascript" src="./js/thickbox.js"></script>
<script type="text/javascript" src="./js/sifr.js"></script>
<script type="text/javascript" src="./js/sifr_sw.js"></script>
<script type="text/javascript" src="./js/scripts.js"></script>
<script type="text/javascript" src="./js/json2.js"></script>
<script type="text/javascript" src="./js/plugins/jquery-ui-1.8.6.custom.min.js"></script>
<script type="text/javascript" src="./js/setDNS1.js"></script>
<!-- [if IE] -->
<script language="javascript" type="text/javascript" src="./js/excanvas.min.js"></script>
<!-- [endif] -->
<!-- for dateAxisRenderer.js -->
<script language="javascript" type="text/javascript" src="./js/plugins/Date.min.js"></script>
<!-- BEGIN: load jqplot -->
<script language="javascript" type="text/javascript" src="./js/jquery.jqplot.min.js"></script>
<script language="javascript" type="text/javascript" src="./js/plugins/jqplot.dateAxisRenderer.js"></script>
<script language="javascript" type="text/javascript" src="./js/plugins/jqplot.barRenderer.js"></script>
<script language="javascript" type="text/javascript" src="./js/plugins/jqplot.categoryAxisRenderer.js"></script>
<!-- END: load jqplot -->
<!-- BEGIN: load slider -->
<script language="javascript" type="text/javascript" src="./js/plugins/slider/jquery.ui.core.js"></script>
<script language="javascript" type="text/javascript" src="./js/plugins/slider/jquery.ui.widget.js"></script>
<script language="javascript" type="text/javascript" src="./js/plugins/slider/jquery.ui.mouse.js"></script>
<script language="javascript" type="text/javascript" src="./js/plugins/slider/jquery.ui.slider.js"></script>
<!-- END: load slider -->
<!-- BEGIN: Uhrzeit -->
<script language="javascript" type="text/javascript">
var timestampunterschied = 1685263190 * 1000 - new Date().getTime();
</script>
<script src="./js/uhrzeit.js" type="text/javascript" language="javascript"></script>
<!-- END: Uhrzeit -->
</head>
<body>
<div id="header">
<div class="head curdef">
<div id="meta">
<div id="login">
</div>
</div>
<div class="eingestelle_sprache"><strong><a href="?s=5,3" style="color:white">DEUTSCH</a></strong></div>
<div id="Uhrzeit"></div>
<div class="title">
<a href="." onclick="return checkChanges(this);" title="zur Startseite">
<img src="./pics/title.png" alt="Servicewelt" />
</a>
<div style="position: relative; color: #97B765; font-weight: 900; margin: 18px 0px 0px 323px;"></div>
</div>
<div class="logo"><a href="." onclick="return checkChanges(this);" title="zur Startseite" class="home_link"> </a></div>
</div>
</div>
<div class="container" id="page">
<div id="main" >
<div id="SpacerFirefox"></div>
<div id="nav">
<div class="clear"></div>
<div class="nav left defaultfirst">
<div class="l left"> </div>
<div class="c left link1">
<a onclick="return checkChanges(this);" href="?s=0">START</a>
</div>
<div class="r left"> </div>
<div class="clear"></div>
</div>
<div class="nav left default parent">
<div class="l left"> </div>
<div class="c left link2">
<a >INFO</a>
</div>
<div class="r left"> </div>
<div class="clear"></div>
<div class="second">
<ul class="second ">
<li>
<a onclick="return checkChanges(this);" href="?s=1,0">ANLAGE</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=1,1">WÄRMEPUMPE</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=1,2">LIZENZBESTIMMUNGEN</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=1,3">NUTZUNGS- UND DATENSCHUTZRICHTLINIE</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=1,4">BEDIENUNG UND INSTALLATION</a>
</li>
</ul>
</div>
</div>
<div class="nav left default parent">
<div class="l left"> </div>
<div class="c left link3">
<a >DIAGNOSE</a>
</div>
<div class="r left"> </div>
<div class="clear"></div>
<div class="second">
<ul class="second ">
<li>
<a onclick="return checkChanges(this);" href="?s=2,0">STATUS</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=2,1">INBETRIEBNAHME</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=2,2">FEHLERLISTE</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=2,3">FACHMANN</a>
</li>
</ul>
</div>
</div>
<div class="nav left default parent">
<div class="l left"> </div>
<div class="c left link4">
<a >PROGRAMME</a>
</div>
<div class="r left"> </div>
<div class="clear"></div>
<div class="second">
<ul class="second ">
<li>
<a onclick="return checkChanges(this);" href="?s=3,0">HEIZPROGRAMM</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=3,1">WARMWASSERPROGRAMM</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=3,2">LÜFTERPROGRAMM</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=3,3">PARTYPROGRAMM</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=3,4">FERIENPROGRAMM</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=3,5">KÜHLZEIT</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=3,6">ANTILEGIONELLENZEIT</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=3,8">GRUNDEINSTELLUNG</a>
</li>
</ul>
</div>
</div>
<div class="nav left default parent">
<div class="l left"> </div>
<div class="c left link5">
<a >EINSTELLUNGEN</a>
</div>
<div class="r left"> </div>
<div class="clear"></div>
<div class="second">
<ul class="second ">
<li>
<a onclick="return checkChanges(this);" href="?s=4,0">HEIZEN</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=4,1">WARMWASSER</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=4,2">LÜFTEN</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=4,3">KÜHLEN</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=4,4">SOLAR</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=4,5">ENERGIEMANAGEMENT</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=4,6">ZEIT/DATUM</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=4,7">INBETRIEBNAHME</a>
</li>
</ul>
</div>
</div>
<div class="nav left defaultlast parent">
<div class="l left"> </div>
<div class="c left link6">
<a >Profil</a>
</div>
<div class="r left"> </div>
<div class="clear"></div>
<div class="second">
<ul class="second last">
<li>
<a onclick="return checkChanges(this);" href="?s=5,0">Netzwerk</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=5,1">Sicherheit</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=5,2">Anlagenbild</a>
</li>
<li>
<a onclick="return checkChanges(this);" href="?s=5,3">SPRACHE</a>
</li>
</ul>
</div>
</div>
<div class="clear"></div>
</div>
<div id="sub_nav" class="span-24"><div class="left main sifr span-9" style="width: 45%">HEIZEN</div>
<div class="span-15 last">
<div class="nav default right" style="text-align:center;padding:0;" id="subsubnavicon">
<a style="background-image:none;"><img src="pics/sub_nav_default_bg_bot_2.gif"></a>
<div id="subsubnav" class="right" style="position:absolute; left:0px; background: url('pics/sub_sub_nav_bg_left.gif') repeat-y scroll 0pt 0pt white; z-index:99; display:none;margin-left:-5px;margin-top;2px">
<div class="nav default right" style="padding-right:25px;padding-bottom:5px;width:100%;float:left">
<div style="margin:auto;width:80%;background-color:#bbbdbe;height:1px;line-height:1px">
<img src="pics/sub_sub_nav_underline_r.gif" class="right">
<img src="pics/sub_sub_nav_underline_l.gif" class="left">
</div>
<a class="left" style="white-space:nowrap" href="?s=4,0,1" onclick="return checkChanges(this);">RAUMTEMPERATUREN HK2</a>
</div>
<div class="nav default right" style="padding-right:25px;padding-bottom:5px;width:100%;float:left">
<div style="margin:auto;width:80%;background-color:#bbbdbe;height:1px;line-height:1px">
<img src="pics/sub_sub_nav_underline_r.gif" class="right">
<img src="pics/sub_sub_nav_underline_l.gif" class="left">
</div>
<a class="left" style="white-space:nowrap" href="?s=4,0,2" onclick="return checkChanges(this);">HEIZKURVE HK1</a>
</div>
<div class="nav default right" style="padding-right:25px;padding-bottom:5px;width:100%;float:left">
<div style="margin:auto;width:80%;background-color:#bbbdbe;height:1px;line-height:1px">
<img src="pics/sub_sub_nav_underline_r.gif" class="right">
<img src="pics/sub_sub_nav_underline_l.gif" class="left">
</div>
<a class="left" style="white-space:nowrap" href="?s=4,0,3" onclick="return checkChanges(this);">HEIZKURVE HK2</a>
</div>
<div class="nav default right" style="padding-right:25px;padding-bottom:5px;width:100%;float:left">
<div style="margin:auto;width:80%;background-color:#bbbdbe;height:1px;line-height:1px">
<img src="pics/sub_sub_nav_underline_r.gif" class="right">
<img src="pics/sub_sub_nav_underline_l.gif" class="left">
</div>
<a class="left" style="white-space:nowrap" href="?s=4,0,4" onclick="return checkChanges(this);">GRUNDEINSTELLUNG</a>
</div>
<div class="right" style="height: 7px; width: 100%; background-image: url('pics/sub_sub_nav_bg_bot.gif');">
<img src="pics/sub_sub_nav_bg_round_top_right.gif" class="left">
</div>
</div>
</div>
<div class="nav active right">
<div class="l"></div>
<div class="c">
<a id="subnavactivename"></a>
</div>
<div class="r"></div>
<div class="clear"></div>
</div>
<script type="text/javascript">
$("#subnavactivename").html('RAUMTEMPERATUREN HK1');
$("#subsubnavicon").css( 'width', function(){
return parseInt( $("#subsubnav").css('width'));
}).click(function(e){
$("#subsubnav").slideToggle('fast');
e.stopPropagation();
});
$("#subsubnav").click(function(e){
e.stopPropagation();
});
$('body').bind('click', function(e) {
$("#subsubnav").slideUp('fast');
});
</script>
</div>
<div class="clear"></div></div>
<form id="werte" action="#" onsubmit="saveValues(this);return false;"><div id="content">
<script type="text/javascript">
var valSettings = new Array();
var jsvalues = new Array();
var jsobj;
</script>
<div class="focusguard" id="focusguard-1" tabindex="0"></div>
<div class="calibration round span-24 last" id="calval5">
<div class="span-7 ialigned">
<h3 class="title">RAUMTEMP. TAG</h3>
</div>
<div class="values span-7">
<div class="editors">
<a onmousedown="change('val5','+',10,30,'0.1',true);return false;" href="javascript://">
<img src="./pics/button_higher.png">
</a>
<a id="editorslower" onmousedown="change('val5','-',10,30,'0.1',true);return false;" href="javascript://" style="clear:left;">
<img src="./pics/button_lower.png">
</a>
</div>
<input type="text" tabindex="1" value="" name="val5" id="val5" class="edit upndown firstElement" style="width:3.6em">
<script language="javascript" type="text/javascript">
valSettings['val5'] = new Array();
valSettings['val5']['type'] = 'float'; valSettings['val5']['min'] = '10';
valSettings['val5']['max'] = '30';
jsvalues['5'] = new Array();
jsvalues['5']['id']='val5';
jsvalues['5']['val']='21,5';
</script>
</div>
<div class="values span-1 append-1">°C</div>
<div class="green round-right span-8 last">
<p>Gültige Werte: Eingabe zwischen<br />10 °C und 30 °C</p>
</div>
</div> <div class="calibration round span-24 last" id="calval7">
<div class="span-7 ialigned">
<h3 class="title">RAUMTEMP. NACHT</h3>
</div>
<div class="values span-7">
<div class="editors">
<a onmousedown="change('val7','+',10,30,'0.1',true);return false;" href="javascript://">
<img src="./pics/button_higher.png">
</a>
<a id="editorslower" onmousedown="change('val7','-',10,30,'0.1',true);return false;" href="javascript://" style="clear:left;">
<img src="./pics/button_lower.png">
</a>
</div>
<input type="text" tabindex="2" value="" name="val7" id="val7" class="edit upndown" style="width:3.6em">
<script language="javascript" type="text/javascript">
valSettings['val7'] = new Array();
valSettings['val7']['type'] = 'float'; valSettings['val7']['min'] = '10';
valSettings['val7']['max'] = '30';
jsvalues['7'] = new Array();
jsvalues['7']['id']='val7';
jsvalues['7']['val']='21,5';
</script>
</div>
<div class="values span-1 append-1">°C</div>
<div class="green round-right span-8 last">
<p>Gültige Werte: Eingabe zwischen<br />10 °C und 30 °C</p>
</div>
</div> <div class="calibration round span-24 last" id="calval58">
<div class="span-7 ialigned">
<h3 class="title">RAUMTEMP. BEREITSCHAFT</h3>
</div>
<div class="values span-7">
<div class="editors">
<a onmousedown="change('val58','+',10,30,'0.1',true);return false;" href="javascript://">
<img src="./pics/button_higher.png">
</a>
<a id="editorslower" onmousedown="change('val58','-',10,30,'0.1',true);return false;" href="javascript://" style="clear:left;">
<img src="./pics/button_lower.png">
</a>
</div>
<input type="text" tabindex="3" value="" name="val58" id="val58" class="edit upndown" style="width:3.6em">
<script language="javascript" type="text/javascript">
valSettings['val58'] = new Array();
valSettings['val58']['type'] = 'float'; valSettings['val58']['min'] = '10';
valSettings['val58']['max'] = '30';
jsvalues['58'] = new Array();
jsvalues['58']['id']='val58';
jsvalues['58']['val']='10,0';
</script>
</div>
<div class="values span-1 append-1">°C</div>
<div class="green round-right span-8 last">
<p>Gültige Werte: Eingabe zwischen<br />10 °C und 30 °C</p>
</div>
</div> <div class="calibration round span-24 last" id="calval54">
<div class="span-7 ialigned">
<h3 class="title">HEIZKREISSOLL HAND</h3>
</div>
<div class="values span-7">
<div class="editors">
<a onmousedown="change('val54','+',10,65,'0.5',true);return false;" href="javascript://">
<img src="./pics/button_higher.png">
</a>
<a id="editorslower" onmousedown="change('val54','-',10,65,'0.5',true);return false;" href="javascript://" style="clear:left;">
<img src="./pics/button_lower.png">
</a>
</div>
<input type="text" tabindex="4" value="" name="val54" id="val54" class="edit upndown lastElement" style="width:3.6em">
<script language="javascript" type="text/javascript">
valSettings['val54'] = new Array();
valSettings['val54']['type'] = 'float'; valSettings['val54']['min'] = '10';
valSettings['val54']['max'] = '65';
jsvalues['54'] = new Array();
jsvalues['54']['id']='val54';
jsvalues['54']['val']='19,5';
</script>
</div>
<div class="values span-1 append-1">°C</div>
<div class="green round-right span-8 last">
<p>Gültige Werte: Eingabe zwischen<br />10 °C und 65 °C</p>
</div>
</div> <div class="calibration round span-24 last" id="calval14">
<div class="span-7 ialigned">
<h3 class="title">RAUMISTTEMP</h3>
</div>
<div class="values span-7">
<div class="info_alone" style="width:3.6em">23,7</div>
</div>
<div class="values span-1 append-1">°C</div>
<div class="green round-right span-8 last">
<p></p>
</div>
</div>
<div class="focusguard" id="focusguard-2" tabindex="5"></div>
<div class="span-24 last">
<div class="span-4 right">
<div class="button left" onclick="document.forms['werte'].onsubmit();"><div class="bg_r"> </div><a>Speichern</a></div> </div>
</div>
<div class="span-24 last"><p></p></div>
<script type="text/javascript">
$( document ).ready(function() {
$('#focusguard-1').focus( function() {
// "last" focus guard got focus: set focus to the first field
$('.lastElement').focus();
$('.lastElement').select();
});
$('#focusguard-2').focus( function() {
// "first" focus guard got focus: set focus to the last field
$('.firstElement').focus();
$('.firstElement').select();
});
});
</script>
</div> </form></div>
</div>
</div>
</div>
<div id="footer">
<!--[if IE]>
<style type="text/css">
#footer
{
height:260px;
}
#versionsNummer
{
position:relative;
top:-33px;
}
</style>
<![endif]-->
<div class="span-24 last footer_middle curdef">
<div class="span-8 prepend-top" style="height:145px">
<div class="span-3">
<img src="./pics/ste_footer_website.png" />
</div>
<div class="span-5 last">
<p>
Weitere Informationen zu unserem Produktprogramm und aktuelle Serviceangebote finden Sie unter <a href="http://www.stiebel-eltron.de" target="_blank" class="extern">www.stiebel-eltron.de</a>
</p>
</div>
</div>
<div class="bordered span-1"></div>
<div class="span-6 prepend-top">
<div class="span-2">
<img src="./pics/footer_tel.png" />
</div>
<div class="span-4 last">
<p>
Unsere Service-Hotline erreichen Sie unter<br /><span class="big">05531 702-111</span>
</p>
</div>
</div>
<div class="bordered span-1"></div>
<div class="span-7 prepend-top last">
<p>
Das Neueste rund um die Servicewelt <br /><a href="http://www.stiebel-eltron.de/erneuerbare-energien/kundenservice/servicewelt/isg/" target="_blank" class="extern">servicewelt</a>
</p>
</div>
</div>
<div class="links span-23 prepend-top append-1 last footer_middle">
<div class="span-17">
<a class="intern" href="?forcepage=dsgvo" onclick="return checkChanges(this);">Datenschutz</a>
<a href="http://www.stiebel-eltron.de/de/info/impressum.html">Impressum</a>
<p style="margin-top:8px" class="right" id="versionsNummer">v12.2.1</p>
</div>
<div class="copyright span-6 last curdef">
© STIEBEL ELTRON 2023 </div>
</div>
</div>
</body>
</html>
To meet the same structure as here it would be the best to get out an array like [title1, value1, title2, value2, ...]
Best Regards
Michael
