20 Buttons and one Form with different Subjects

I have 20 different buttons and I have one pupup divi contact form. The Subject of the Form, should reflect a value realted to the button that has been pressed.

I have found https://divimode.com/knowledge-base/divi-areas-script-generator/ and I tried to use this script to automatically hide a certain field and show another <div id=”formheader”> tag with the read only information of the hidden field.

<div id="formheader"></div>
<script>
(function() {
  DiviArea.addAction('show_area', function(area) {   
    if (! area.hasId('#PopupAnmeldungContactForm')) { return; }
    var dynamictext= 'Hello Worlds';
    var theField = area.get('input[name="et_pb_contact_fieldtitle_1"]');
    theField.val(kleingruppe);
    document.getElementById('et_pb_contact_fieldtitle_1').style.display = 'none';
		document.getElementById('formheader').innerHTML = '<h3>' + dynamictext + '</h3>';
  });
})();
</script>

I have not found out how I could make the dynamictext really something related to the button thjat has been pressed. So far the script is working ans the form is presented with a read only title/subject that is called Hello Worlds.

I tried already to add on the button a link parameter like this #mypluginid?title=test and then used this script https://www.sitepoint.com/get-url-parameters-with-javascript/ to get the value from the url, but the popup does not work anymore then.

Any other idea how that I can have the value of the button id that was pressed in the scirpt above?

Regards

René

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