// Description: get Text form 'url' and write to div 'id'

var http_request = false;
var target_id = '';

function doRequest(url,id,param)
{
	http_request = false;
	target_id = id;
		
	if (window.XMLHttpRequest)
	{			
		http_request = new XMLHttpRequest();
		
		if (http_request.overrideMimeType)
		{
			http_request.overrideMimeType('text/xml');
		}
	}
	else if (window.ActiveXObject)
	{
		try {http_request = new ActiveXObject("Msxml2.XMLHTTP");}
		catch (e)
		{
			try {http_request = new ActiveXObject("Microsoft.XMLHTTP");}
			catch (e) {}
		}
	}

	if (!http_request)
	{
		alert('Ende :( Kann keine XMLHTTP-Instanz erzeugen');
		return false;
	}
	http_request.onreadystatechange = myHandler1;
	http_request.open('GET', url+"?"+param+"&target_id="+target_id, true);
	http_request.send(null);
}

function myHandler1()
{
	if (http_request.readyState == 4)
	{
		if (http_request.status == 200)
		{
			document.getElementById(target_id).innerHTML = http_request.responseText;
		}
		else
		{
			alert('Bei dem Request ist ein Problem aufgetreten.');
		}
	}
}

////
//Lehrer//
var X = 0, Y = 0;
jQuery(document).ready(function(){
   jQuery(document).mousemove(function(e){
        X = e.pageX;
        Y = e.pageY;
   }); 
})

function showLehrerLayer(layerID,url,id,param)
{
    document.getElementById(layerID).style.display = 'block';
    var posX = X-20 + "px";
    var posY = Y-20 + "px";
    document.getElementById(layerID).style.left = posX;
    document.getElementById(layerID).style.top = posY;
    doRequest(url,id,param);
}
function hideLehrerLayer(layerID)
{
    document.getElementById(layerID).style.display = 'none';
}