function fenster(url,breite,hoehe)
{
var url;
var width=breite;
var height=hoehe;
var l = (screen.availWidth - width) / 2; var t = (screen.availHeight - height) / 2; newwindow = window.open(url,"newwindow","width="+breite+",height=" +hoehe+",screenX="+l+",screenY="+t+",left=" +l+",top="+t+",scrollbars=0,resizable=0,menubar=no");
newwindow.focus();
}