function ajax_create ()
{
    var xml_http = false;
	
	try
	{
		xml_http = new ActiveXObject("Msxml2.XMLHTTP");
	}
	catch (e1)
	{
		try
		{
			xml_http = new ActiveXObject("Microsoft.XMLHTTP");
		}
		catch (e2)
		{
			xml_http = false;
		}
	}
	
	if (!xml_http && typeof XMLHttpRequest != 'undefined')
	{
		xml_http = new XMLHttpRequest();
	}
	
	return xml_http; 
}

function ajax_launch (xml_http, url, query_string, response_function)
{
	xml_http.open("POST", url, true);
	xml_http.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	xml_http.onreadystatechange = function ()
	{
		if (xml_http.readyState == 4)
		{
			ajax_active = false;
			
			response_function (xml_http.responseText);
		}
	}
	xml_http.send(query_string);
}