function expandBox(id_nr) {

	// Hide already opened content boxes if any
	var contentDiv = document.getElementById("boxes_wrapper");
	var contents = new Object();
	contents = contentDiv.getElementsByTagName('div');
	for (var i=0; i<contents.length; i++) {
		// Fetch only content elements
		if (contents[i].id.match(/help_+\d+_content/) != null ) {
			contents[i].style.display = (contents[i].id == "help_"+id_nr+"_content") ? "block" : "none" ;		
		}
	}
	
	// Hide selected "Mehr" link
	var wrapperDiv = document.getElementById("boxes_wrapper");
	var mehrLinks = new Object();
	mehrLinks = wrapperDiv.getElementsByTagName('a');
	for (var i=0; i<mehrLinks.length; i++) {
		if (mehrLinks[i].id.match(/help_+\d+_more/) != null) {
			mehrLinks[i].style.display = (mehrLinks[i].id == "help_"+id_nr+"_more") ? "none" : "block";
		}
	}

	// Underline selected submenu link
	var submenu = document.getElementById("hilfe_submenu");
	var links = new Object();
	links = submenu.getElementsByTagName('a');
	for (var i=0; i<links.length; i++) {
		links[i].style.textDecoration = (links[i].id == "sublink_help_"+id_nr) ? "underline" : "none";
	}
	
}