function createRequest() {
 var request = null;
 try {
   request = new XMLHttpRequest();
 } catch (trymicrosoft) {
   try {
	 request = new ActiveXObject("Msxml2.XMLHTTP");
   } catch (othermicrosoft) {
	 try {
	   request = new ActiveXObject("Microsoft.XMLHTTP");
	 } catch (failed) {
	   request = null;
	 }
   }
 }

 if (request == null) {alert("There was an Error, please try again");} 
 else {return request;} 
} // Construct AJAX Object - will work for both POST and GET


function sendAJAXRequest(parameters) 
{
	// sendAJAXRequest ("function=save-document");
	 var url = "includes/php/ajax-engine.php";						/* this is the page we are calling 	*/
	 
 	 request = createRequest();
	 request.open("POST", url, true); 				/* this line initiates the connection using GET as opposed to POST	*/
	 request.onreadystatechange = getXMLRequest; 		/* when the server returns data, function updatepage is called 		*/
	 request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");	 
	 request.send(parameters);
}


function getXMLRequest ()
{
  if (request.readyState == 4) 
  {
		if (request.status == 200) 
		{
			// Get the updated result from the XML response
			var xmlDoc = request.responseXML;
	
			requestedFunction = xmlDoc.getElementsByTagName ("function")[0].firstChild.nodeValue;			
			if (requestedFunction == "tweet-it")
			{
				updateTweetIt (xmlDoc);				
			}	
		}		
	}
}