var xmlHttp

function getCategory(str)
{
	var category = document.form_category.category.value;
 	
 	xmlHttp = GetXmlHttpObject()
 	
 	if (xmlHttp==null)
 	{
		alert ("Browser does not support HTTP Request")
		return
  	}
  	
	var url="scripts/article_category.php"
	url=url+"?q="+str
	url=url+"&sid="+Math.random();
	url = url + "&category=" + category;
	xmlHttp.onreadystatechange=stateChanged 
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
}

function stateChanged() 
{
	document.getElementById("articles").innerHTML = xmlHttp.readyState;

	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 	{ 
 		document.getElementById("articles").innerHTML = xmlHttp.responseText;
 	}
 	else
 	{
 		document.getElementById("articles").innerHTML = "";
 	}
}

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;
}