var xmlHttp

function SetForm(which)
{ 
	catId = which.value
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
	{
		alert ("Browser does not support HTTP Request")
		return
	} 
	var url="DisplayForm.php?catId="+catId
	xmlHttp.onreadystatechange=stateChanged 
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
}
function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	{ 
		document.getElementById("adForm").innerHTML=xmlHttp.responseText 
	} 
} 

function GetXmlHttpObject()
{ 
	var objXMLHttp=null
	if (window.XMLHttpRequest)
	{
		objXMLHttp=new XMLHttpRequest()
	}
	else if (window.ActiveXObject)
	{
		objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP")
	}
return objXMLHttp
}