function getNr(url){
alert("XMLHTTP")
  var c =0;
  if (window.XMLHttpRequest){// code for IE7+, Firefox, Chrome, Opera, Safari
    xmlhttp=new XMLHttpRequest();
  }else{// code for IE6, IE5
    xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
  xmlhttp.onreadystatechange=function(){
    if (xmlhttp.readyState==4 && xmlhttp.status==200){
      
      x=xmlhttp.responseXML.documentElement.getElementsByTagName("a");
      for (i=0;i<x.length;i++){
        if(x[i].rel=="lightbox"){
          c++;
        }
      }
      alert(c)
      //el.innerHTML="("+c+")";
      }
  }
  xmlhttp.open("GET",url,true);
  xmlhttp.send();
}