Built working GENERAL openpopup() function!
LAURA: To use put the "onclick" attribute in any html element. and call the function openpopup(somedir). Where somedir is the path to any popup content file. E.g.:
<input type="button" onclick="openpopup('popups/help.php')" />
In the file just build standard html. Its just IMPORTANT to wrap everything in there in a <div id="popup_inhalt"></div> (do not wrap it in the <div id="popup"> div. Thanks <3