// JavaScript Document

//does a POST type request
//url: url to request
//postdata: the data to POST
//onsuccess: a function with the form function(xmlhttp, postdata) that executes on successful request
function asyncPost(url, postdata, onsuccess)
{
	var xmlhttp;
  try
	{
		// Firefox, Opera 8.0+, Safari
		xmlhttp=new XMLHttpRequest();
	}
  catch (e)
	{
		// Internet Explorer
		try
		{
			xmlhttp=new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			try
			{
				xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch (e)
			{
				alert("Your browser does not support AJAX!");
				return false;
			}
		}
	}
	xmlhttp.onreadystatechange = function()
	{
		if(xmlhttp.readyState==4)
		{
			if(xmlhttp.status==200)
				onsuccess(xmlhttp, postdata);
			else
				alert('AJAX postback failed! Error code '+xmlhttp.status+': '+xmlhttp.statusText);
		}
	}
	xmlhttp.open( "POST", url, true ); 
	xmlhttp.setRequestHeader( 
			'Content-Type', 
			'application/x-www-form-urlencoded; charset=UTF-8' 
	); 
	xmlhttp.send(postdata);
}