function pageWidth() {return window.innerWidth != null? window.innerWidth : document.documentElement && document.documentElement.clientWidth ?  document.documentElement.clientWidth : document.body != null ? document.body.clientWidth : null;} 

function pageHeight() {return  window.innerHeight != null? window.innerHeight : document.documentElement && document.documentElement.clientHeight ?  document.documentElement.clientHeight : document.body != null? document.body.clientHeight : null;} 

function popup(file) {
   var l = Math.floor((pageWidth()-620)/2);
   var t = Math.floor((pageHeight()-500)/2);
   window.open(file,"","width=620"+ ",height=550"+ ",top=" + t + ",left=" + l + ",scrollbars=yes");
   document.getElementById('main').style.opacity='0.2';
   document.getElementById('main').style.filter='alpha(opacity=20)';

}
function terug() {
	opener.document.getElementById('main').style.opacity='1';
	opener.document.getElementById('main').style.filter='alpha(opacity=100)'
}
function MM_goToURL() { //v3.0
  var i, args=MM_goToURL.arguments; document.MM_returnValue = false;
  for (i=0; i<(args.length-1); i+=2) eval(args[i]+".location='"+args[i+1]+"'");
}