var xmlHttp

function showOption(str)
{ 
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
	 {
		 alert ("Browser does not support HTTP Request")
		 return
	 }
	var url="getClassOption.php"
	url=url+"?q="+str
	
	xmlHttp.onreadystatechange=stateChanged 
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
}

function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	 { 
	 	document.getElementById("txtHint").innerHTML=xmlHttp.responseText 
	 } 
}

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