function createRequest() {
     try {
       xmlhttp = new XMLHttpRequest();
     } catch (trymicrosoft) {
       try {
         xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
       } catch (othermicrosoft) {
         try {
           xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
         } catch (failed) {
           xmlhttp = null;
         }
       }
     }

     if (xmlhttp == null)
       alert("Error creating request object!");
   }
   
  function showProductSpec(str) {
    if (str=="") {
      document.getElementById("txtHint").innerHTML="";
      return;
    }
    
    createRequest();
    
    xmlhttp.onreadystatechange=function() {
      if (xmlhttp.readyState==4 && xmlhttp.status==200) {
        document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
       }
    }
     
        xmlhttp.open("GET","result.php?q="+str,true);
         
   
        xmlhttp.send(null);
    }