function getDataServer(url, vars){
     var xml = null;
     try{
         xml = new ActiveXObject("Microsoft.XMLHTTP");
     }catch(expeption){
         xml = new XMLHttpRequest();
     }
     xml.open("GET",url + vars, false);
     xml.send(null);
     if(xml.status == 404) alert("Balio gabeko helbidea");
     return xml.responseText;
}