function createXMLHTTPObject ( )
{
	var XMLHttpFactories = [
		function ( ) { return new XMLHttpRequest( ) },
		function ( ) { return new ActiveXObject ( "Msxml2.XMLHTTP" ) },
		function ( ) { return new ActiveXObject ( "Msxml3.XMLHTTP" ) },
		function ( ) { return new ActiveXObject ( "Microsoft.XMLHTTP" ) }
	];
	var xmlhttp = false;
	
	for ( var i = 0; i < XMLHttpFactories.length; i++ )
	{
		try 
		{ 
			xmlhttp = XMLHttpFactories[i]( ); 
		} 
		catch (error) 
		{
			continue;
		}
		break;
	}
	
	return xmlhttp;
}

function sendRequest ( url, callback )
{
	var req = createXMLHTTPObject ( );
	if ( !req ) return;
	
	req.open ( "GET", url, true );
	req.onreadystatechange = function ( )
	{
		if ( req.readyState != 4 ) return;
		if ( req.status != 200 && req.status != 304 ) 
		{
			alert ( "HTTP error " + req.status );
			return;
		}
		callback ( req );
	}
	if ( req.readyState == 4 ) return;
	req.send ( null );
}

function xmlhttp_start ()
{
	var req = createXMLHTTPObject ( );
	if ( !req ) return;
	
	// In welke <a>-tags zijn we geinteresseerd?
	var e = document.getElementById( 'menulijst' );
	if ( !e ) alert ("Error xmlhttp_start");
	var links = e.getElementsByTagName ( 'a' );
	
	// Sla eerste link over, die verwijst naar Home (buiten het submenu)
	// Sla laatste link (BUY) over, die verwijst naar externe pagina
	for ( var i = 1; i < links.length - 1; i++ )
	{
		// Welke methode aanroepen bij 'klikken'?
		links[i].onclick = function () 
		{ 
			deactiveerMenu ( huidige_pagina );
			var paginaId = this.parentNode.id;
			//if ( paginaId == "home" ) paginaId = "index";
			huidige_pagina = paginaId;
			var url = this.href.replace ( ".php", "_kort.php" );
			sendRequest ( url, showPage );
			return false; 
		};
	}
}

function showPage ( req )
{
	var html = req.responseText;
	document.getElementById ( 'content' ).innerHTML = html;

	// Koppel mp3's in vernieuwde content weer aan de player
	koppelAudio();
	
	activeerMenu ( huidige_pagina );
}	
/*
*/