/*
http://www.webreference.com/programming/javascript/mk/column2/index.html
*/

var dd_u = "undefined";
function WZDD()
{
	this.elements = new Array(0);
	this.obj = null;
	this.n = navigator.userAgent.toLowerCase();
	this.db = (document.compatMode && document.compatMode.toLowerCase() != "backcompat")?
		document.documentElement
		: (document.body || null);
	this.op = !!(window.opera && document.getElementById);
	if(this.op) document.onmousedown = new Function('e',
		'if(((e = e || window.event).target || e.srcElement).tagName == "IMAGE") return false;');
	this.ie = !!(this.n.indexOf("msie") >= 0 && document.all && this.db && !this.op);
	this.iemac = !!(this.ie && this.n.indexOf("mac") >= 0);
	this.ie4 = !!(this.ie && !document.getElementById);
	this.n4 = !!(document.layers && typeof document.classes != dd_u);
	this.n6 = !!(typeof window.getComputedStyle != dd_u && typeof document.createRange != dd_u);
	this.w3c = !!(!this.op && !this.ie && !this.n6 && document.getElementById);
	this.ce = !!(document.captureEvents && document.releaseEvents);
	this.px = this.n4? '' : 'px';
	this.tiv = this.w3c? 40 : 10;
}
var browser = new WZDD();


function mouseCoords(ev){
	if(ev.pageX || ev.pageY){
		return {x:ev.pageX, y:ev.pageY};
	}
	return {
		x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
		y:ev.clientY + document.body.scrollTop  - document.body.clientTop
	};
}

function getMouseOffset(target, ev){
	ev = ev || window.event;

	var docPos    = getPosition(target);
	var mousePos  = mouseCoords(ev);
	return {x:mousePos.x - docPos.x, y:mousePos.y - docPos.y};
}

function getPosition(e){
	var x = document.getElementById('main');

	var left = -230;
	var top = -140;
	left -= x.offsetLeft;
	top -= x.offsetTop;
	
//	var left = -350;
//	var top  = -160;

	while (e.offsetParent){
		left += e.offsetLeft;
		top  += e.offsetTop;
		e     = e.offsetParent;
	}

	left += e.offsetLeft;
	top  += e.offsetTop;

	return {x:left, y:top};
}

function mouseMove(ev){
	ev           = ev || window.event;
	var mousePos = mouseCoords(ev);

	if(dragObject){
		dragObject.style.position = 'absolute';
		dragObject.style.top      = (mousePos.y - mouseOffset.y) + 'px';
		dragObject.style.left     = (mousePos.x - mouseOffset.x) + 'px';

		return false;
	}
}

function makeDraggable(item){
	if(!item) return;
	item.onmousedown = function(ev){
		dragObject  = this;
		mouseOffset = getMouseOffset(this, ev);
		return false;
	}
}

function mouseUp(ev){
	dragObject = null;
}

document.onmousemove = mouseMove;
document.onmouseup   = mouseUp;

var dragObject  = null;
var mouseOffset = null;