var xmlhttp;

function queryAddress(str,field,target)
{
if(field == 'state'){
	document.getElementById('ajaxState').innerHTML='';
	document.getElementById('ajaxCity').innerHTML='';
} 
if(field == 'city'){
	document.getElementById('ajaxCity').innerHTML='';
}
xmlhttp=GetXmlHttpObject();
if (xmlhttp==null)
  {
  alert ("Browser does not support HTTP Request");
  return;
  }
var url="ajax.php";
url=url+"?q="+str;
url=url+"&field="+field;
url=url+"&sid="+Math.random();
//xmlhttp.onreadystatechange=stateChanged;
xmlhttp.onreadystatechange= function() { stateChanged(target); };
xmlhttp.open("GET",url,true);
xmlhttp.send(null);
}

function stateChanged(target)
{
if (xmlhttp.readyState==4)
{
document.getElementById(target).innerHTML=xmlhttp.responseText;
}
}

function GetXmlHttpObject()
{
if (window.XMLHttpRequest)
  {
  // code for IE7+, Firefox, Chrome, Opera, Safari
  return new XMLHttpRequest();
  }
if (window.ActiveXObject)
  {
  // code for IE6, IE5
  return new ActiveXObject("Microsoft.XMLHTTP");
  }
return null;
}