var mousex = 0;
var mousey = 0;
var grabx = 0;
var graby = 0;
var orix = 0;
var oriy = 0;
var elex = 0;
var eley = 0;
var algor = 0;

var dragobj = null;

function falsefunc() { return false; } // used to block cascading events
/*
function init()
{
document.onmousemove = update; // update(event) implied on NS, update(null) implied on IE
update();
}
*/
function getMouseXY(e) // works on IE6,FF,Moz,Opera7
{
	if (!e) e = window.event; // works on IE, but not NS (we rely on NS passing us the event)

	if (e)
	{
		if (e.pageX || e.pageY)
		{ // this doesn't work on IE6!! (works on FF,Moz,Opera7)
			mousex = e.pageX;
			mousey = e.pageY;
			algor = '[e.pageX]';
			if (e.clientX || e.clientY) algor += ' [e.clientX] '
		}
		else if (e.clientX || e.clientY)
		{ // works on IE6,FF,Moz,Opera7
			// Note: I am adding together both the "body" and "documentElement" scroll positions
			//       this lets me cover for the quirks that happen based on the "doctype" of the html page.
			//         (example: IE6 in compatibility mode or strict)
			//       Based on the different ways that IE,FF,Moz,Opera use these ScrollValues for body and documentElement
			//       it looks like they will fill EITHER ONE SCROLL VALUE OR THE OTHER, NOT BOTH
			//         (from info at http://www.quirksmode.org/js/doctypes.html)
			mousex = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
			mousey = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;
			algor = '[e.clientX]';
			if (e.pageX || e.pageY) algor += ' [e.pageX] '
		}
	}


}
/*
function update(e)
{
getMouseXY(e); // NS is passing (event), while IE is passing (null)

document.getElementById('span_browser').innerHTML = navigator.appName;
document.getElementById('span_winevent').innerHTML = window.event ? window.event.type : '(na)';
document.getElementById('span_autevent').innerHTML = e ? e.type : '(na)';
document.getElementById('span_mousex').innerHTML = mousex;
document.getElementById('span_mousey').innerHTML = mousey;
document.getElementById('span_grabx').innerHTML = grabx;
document.getElementById('span_graby').innerHTML = graby;
document.getElementById('span_orix').innerHTML = orix;
document.getElementById('span_oriy').innerHTML = oriy;
document.getElementById('span_elex').innerHTML = elex;
document.getElementById('span_eley').innerHTML = eley;
document.getElementById('span_algor').innerHTML = algor;
document.getElementById('span_dragobj').innerHTML = dragobj ? (dragobj.id ? dragobj.id : 'unnamed object') : '(null)';
}
*/
function grab(divid)
{

	context=document.getElementById(divid);
	document.onmousedown = falsefunc; // in NS this prevents cascading of events, thus disabling text selection
	dragobj = context;
	// dragobj.style.zIndex = 1000; // move it to the top
	document.onmousemove = drag;
	document.onmouseup = drop;
	elex = orix = dragobj.offsetLeft;
	eley = oriy = dragobj.offsetTop;

	//orix=orix - 100 ;
	// oriy=oriy - 60 ;
	getMouseXY();
}

function drag(e) // parameter passing is important for NS family
{
	if (!grabx && !graby) {
		grabx = mousex;
		graby = mousey;

	}
	if (dragobj)
	{
		elex = orix + (mousex-grabx);
		eley = oriy + (mousey-graby);
		if (eley<0) eley=0;
		if (eley>document.documentElement.clientHeight) eley=document.documentElement.clientHeight-50;
		
		if (elex<-200) elex=-200;
		if (eley>document.documentElement.clientWidth) eley=document.documentElement.clientWidth-50;
		
		dragobj.style.position = "absolute";
		dragobj.style.left = (elex).toString(10) + 'px';
		dragobj.style.top  = (eley).toString(10) + 'px';
		//document.getElementById('messagediv').innerHTML=dragobj.id + ' ' + elex + ' ' + eley + ' ' + Math.random();
	}
	getMouseXY(e);
	return false; // in IE this prevents cascading of events, thus text selection is disabled
}

function drop()
{
	if (dragobj)
	{
		//dragobj.style.zIndex = 0;
		dragobj = null;
	}
	grabx = 0;
	graby = 0;
	getMouseXY();
	document.onmousemove = null;
	document.onmouseup = null;
	document.onmousedown = null;   // re-enables text selection on NS
}