function fensteroeffner(seite,mywidth,myheight,scroller,mytool,myresize){
var winbreite = (screen.width - mywidth)/2;
var winhoehe = (screen.height - myheight)/2;
var myposition = "screenX="+winbreite+",screenY="+winhoehe+",top="+winhoehe+",left="+winbreite;
var myparms="width="+mywidth+",height="+myheight+",scrollbars="+scroller+",toolbar="+mytool+",resizable="+myresize+","+myposition;
 fenster = window.open('','',myparms);
 fenster.location.href = seite;
 fenster.focus();
 }