var xmlHttp

function setregiontowns(regionid)
{ 
var url="ajax_buildtownbyregion.asp?regionid=" + regionid
xmlHttp=GetXmlHttpObject(buildtownlist)
xmlHttp.open("GET", url , true)
xmlHttp.send(null)
} 

function buildtownlist() 
{ 
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	{
	document.getElementById('townlist').innerHTML = xmlHttp.responseText;
	} 
}

function GetXmlHttpObject(handler)
{ 
	var objXmlHttp=null

	if (navigator.userAgent.indexOf("Opera")>=0)
		{
		alert("This example doesn't work in Opera") 
		return 
		}
	if (navigator.userAgent.indexOf("MSIE")>=0)
	{ 
		var strName="Msxml2.XMLHTTP"
		if (navigator.appVersion.indexOf("MSIE 5.5")>=0)
			{
			strName="Microsoft.XMLHTTP"
			} 
		try
			{ 
			objXmlHttp=new ActiveXObject(strName)
			objXmlHttp.onreadystatechange=handler 
			return objXmlHttp
			} 
			catch(e)
			{ 
			alert("Error. Scripting for ActiveX might be disabled") 
			return 
			} 
	} 
	if (navigator.userAgent.indexOf("Mozilla")>=0)
	{
		objXmlHttp=new XMLHttpRequest()
		objXmlHttp.onload=handler
		objXmlHttp.onerror=handler 
		return objXmlHttp
	}
}