var xmlHttp

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

function stateChanged() 
{
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 	{ 
 		document.getElementById("preview").innerHTML = "<h2>Preview Message</h2><div id='post'>Feature in development</div>"; //xmlHttp.responseText
 	}
 	else
 	{
 		document.getElementById("preview").innerHTML = "Processing..."
 	}
}

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;
}