function comment_preview()
{
	document.getElementById('comment_preview_head').innerHTML = 'Vorschau - Bitte warten';
	var text = document.getElementById('form_comment_text').value;
	if(text.length > 0) { 
		var req = xmlreq();
		req.open("GET", geturl() + 'content/php_ajax/ajax_preview.php?text='+escape(encodeURI(text)), true);
	
		req.onreadystatechange = function(){ //<-- anonyme funktion
			switch(req.readyState) {
				case 4:
					if(req.status!=200) {
						//document.getElementById('comment_preview_text').innerHTML = '<span style="color:red;">Error: '+req.status+'</span>';
					}else{
						var xml = req.responseXML;
						var r_text = resp(xml, 'preview_text');
						document.getElementById('comment_preview_text').innerHTML = r_text;
						document.getElementById('comment_preview_head').innerHTML = 'Vorschau';
						document.getElementById('comment_preview_head').style.visibility = 'visible';
						document.getElementById('comment_preview_text').style.visibility = 'visible';
					}
				break;
		
				default:
					return false;
				break;
			}
		};
	} else { // textlength == 0
		document.getElementById('comment_preview_text').innerHTML = '';
		document.getElementById('comment_preview_head').style.visibility = 'hidden';
		document.getElementById('comment_preview_text').style.visibility = 'hidden';
	}

	req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	req.send(null);

}