var pw;
function popup(url,w,h,opts) {
  if (!w) w=620;
  if (!h) h=320;
  var sw=800, sh=572;
  if (window.screen) {
    sw=screen.availWidth;
    sh=screen.availHeight - 75;
  }
  sw-=15;
  sh-=50;
  if (w>sw) w=sw;
  if (h>sh) h=sh;
  var t=190;
  var l=sw-w;
  if (l<0) l=0;
  if (t+h>sh) t=sh-h;

  
  var id="w"+w+"h"+h;
  if (opts) {
    var i=opts.indexOf("id=");
    if (i>=0) {
      var j=opts.indexOf(",",i);
      if (j<0)
        j=opts.length;
      id=opts.substring(i+3,j);
    }
  }
  var f=1;
  var exturl=url.indexOf("http:")!=-1&&url.substring(0,i)!=location.href.substring(0,i);
  if(!exturl)id="pop_"+id;
  if (!window.focus||(exturl&&navigator.userAgent.indexOf("MSIE 4")>=0)) {
    if(pw){
	 pw=window.open('',id,"top=9999,left=9999,width=0,height=0");pw.close();
	 pw=null;setTimeout("popup('"+url+"',"+w+","+h+(opts?",'"+opts+"'":"")+")",1);
	 return;
    }
    f=0
  }
  var parm3="alwaysRaised=1";
  parm3+=",dependent="+(opts&&opts.indexOf("dependent=yes")!=-1?"yes":"no");
  parm3+=",directories="+(opts&&opts.indexOf("directories=yes")!=-1?"yes":"no");
  parm3+=",hotkeys="+(opts&&opts.indexOf("hotkeys=yes")!=-1?"yes":"no");
  parm3+=",width="+w;
  parm3+=",height="+h;
  parm3+=",location="+(opts&&opts.indexOf("location=yes")!=-1?"yes":"no");
  parm3+=",menubar="+(opts&&opts.indexOf("menubar=no")!=-1?"no":"yes"); //ps: 14-11-2003, standaard aangezet
  parm3+=",resizable="+(opts&&opts.indexOf("resizable=no")!=-1?"no":"yes");
  parm3+=",scrollbars="+(opts&&opts.indexOf("scrollbars=no")!=-1?"no":"yes");
  parm3+=",status="+(opts&&opts.indexOf("status=no")!=-1?"no":"yes");
  parm3+=",titlebar="+(opts&&opts.indexOf("titlebar=no")!=-1?"no":"yes");
  parm3+=",toolbar="+(opts&&opts.indexOf("toolbar=yes")!=-1?"yes":"no");
  parm3+=",left="+l;
  parm3+=",top="+t;
  pw=window.open(url,id,parm3);
  if(pw&&pw.focus)pw.focus();
}