// Globale Variablen
var w3c = document.getElementById&&!document.all?1:0;
var ie = document.all?1:0;
var draggable = false;
var box, mouseX, mouseY;

function startdrag(e,boxID) {
	box = document.getElementById(boxID);
	
	
	levelIndex++;
	//box.style.zIndex = levelIndex; 
	
	draggable = true;
	if(e.cancelable) { e.preventDefault(); }
	
	if(!e) e = window.event; 
	e.returnValue = false;
	 
	// Mausposition berechnen
	mouseX = e.clientX - box.offsetLeft;
	mouseY = e.clientY - box.offsetTop;
	
	// Beim Verschieben drag() abarbeiten
	document.onmousemove = drag;
	// Beim Ablegen drop() abarbeiten
	document.onmouseup = drop;
}

function drag(e) { 

	if(draggable == true) {
		var e = e || window.event;
		box.style.left= (e.clientX - mouseX) + "px";
		box.style.top = (e.clientY - mouseY) + "px";
	}
	return false;
}

function drop() { 
	draggable = false;
	document.onmousemove = null;
}