function GetXmlHttpObject()
{
	var xmlHttp=null;
	try
	{
		xmlHttp=new XMLHttpRequest();
	}
	catch (e)
	{
		try
		{
			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	return xmlHttp;
}
/*
*	Display questions one by one
*/
function DisplayQuestion(nextquestion, curIndex, radio)
{
	var i;
	var ans=0;
	if (radio) 
	{
		
		for(i=0; i<4; ++i)
		{
			if(!DocItem(radio,i)) continue;
			if (DocItem(radio,i).checked)
			{
				ans=DocItem(radio,i).value;//1-4
			}
		}
	}
		
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
  	{
  		alert ("Your browser does not support AJAX!");
  		return;
  	}
	var url="display_question.php?nextquestion="+nextquestion+"&currenquestion="+curIndex+"&curAnswer="+ans;
	url=url+"&sid="+Math.random();
	xmlHttp.onreadystatechange=UpdateQuestionDisplay;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
}
function DisplayStatus(id)
{
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
  	{
  		alert ("Your browser does not support AJAX!");
  		return;
  	}
	var url="display_status.php?index="+id;
	xmlHttp.onreadystatechange=UpdateQuestionDisplay;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
}
/*
* Display Reference
*/ 
function DisplayReferance(id,status)
{
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
	{
	 alert ("Your browser does not support AJAX!");
	 return;
	}
	var url="reference.php";
	url=url+"?id="+id+"&status="+status;
	url=url+"&sid="+Math.random();
	xmlHttp.onreadystatechange=UpdateReferenceNote;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
}
function UpdateQuestionDisplay() 
{ 
	if (xmlHttp.readyState==4)
	{ 
		document.getElementById("ajax_disp").innerHTML=xmlHttp.responseText;
	}
}
function UpdateReferenceNote() 
{ 
	if (xmlHttp.readyState==4)
	{ 
		document.getElementById("reference").innerHTML=xmlHttp.responseText;
	}
}

/*
*	User clicked on finish button
*/

function TestFinish(answered, total)
{
	if(total > answered+1) // consider the current question
	{
		if(!confirm("You haven't answered all questions.\nAre you sure you want to finish the test ?'"))
			return;
	}
	DocItem('frmTest').submit();
}