function check_j(obj,job_obj,email_obj,button_obj,a_f_u)
{
  var http;
  //obj.innerHTML="Validating...";
  var job_number=job_obj.value;
  var email=email_obj.value;

  if (typeof XMLHttpRequest != "undefined"){http = new XMLHttpRequest();}
  else if (typeof ActiveXObject != "undefined"){http = new ActiveXObject("MSXML2.XmlHttp");}
  else{alert("No XMLHttpRequest object available. This functionality will not work.");}
  var oHttp = http;
  if (oHttp.readyState != 0){oHttp.abort();}
  var sURL = "check_job_number.php?job_number="+encodeURIComponent(job_number)+"&email="+encodeURIComponent(email);
  oHttp.open("get", sURL , true);
  oHttp.onreadystatechange = function ()
  {
    if (oHttp.readyState == 4)
    {
      //alert(oHttp.responseText);
      try
      {
        var str=oHttp.responseText;
        var r="";
        if(email=="" && job_number=="")
        {
          r="";
          button_obj.disabled=true; a_f_u.style.visibility='hidden';
        }
        else if(str=="valid")
        {
          r="<img src=\"images/positive_coupon_validation.gif\">";
          button_obj.disabled=false; a_f_u.style.visibility='visible';
        }
        else
        {
          r="<img src=\"images/negative_coupon_validation.gif\">";
          button_obj.disabled=true; a_f_u.style.visibility='hidden';
        }
        obj.innerHTML=r;
        //obj.innerHTML=oHttp.responseText;
      }
      catch(e)
      {
        obj.innerHTML="Unable to validate Job Number.";
      }
    }
  };
  oHttp.send(null);
};