var xmlHttp6

function checkpostcode(str)
{
if (str.length==0)
  { 
  document.getElementById("result").innerHTML="";
  return;
  }
xmlHttp6=GetXmlHttpObject6();
if (xmlHttp6==null)
  {
  alert ("Your browser does not support AJAX!");
  return;
  } 
var url="postcode_check.php";
url=url+"?postcode="+str;
url=url+"&sid="+Math.random();
xmlHttp6.onreadystatechange=stateChanged6;
xmlHttp6.open("GET",url,true);
xmlHttp6.send(null);
} 

function stateChanged6() 
{ 
if (xmlHttp6.readyState==4)
{ 
document.getElementById("result").innerHTML=xmlHttp6.responseText;
}
}

function GetXmlHttpObject6()
{
var xmlHttp6=null;
try
  {
  // Firefox, Opera 8.0+, Safari
  xmlHttp6=new XMLHttpRequest();
  }
catch (e)
  {
  // Internet Explorer
  try
    {
    xmlHttp6=new ActiveXObject("Msxml2.XMLHTTP");
    }
  catch (e)
    {
    xmlHttp6=new ActiveXObject("Microsoft.XMLHTTP");
    }
  }
return xmlHttp6;
}