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 mm_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)
  positiontip(e);
/*
  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)';
*/

/*document.getElementById('debug').innerHTML = 'mouse x: '+mousex+' mouse y: '+mousey+'<br>grab x: '+grabx+' grab y: '+graby+'<br>ori x: '+orix+' ori y: '+oriy+'<br>ele x: '+elex+' ele y: '+eley;*/
}

function grab(context)
{
  update();
  document.onmousedown = falsefunc; // in NS this prevents cascading of events, thus disabling text selection
  dragobj = context;
  dragobj.style.zIndex = 10000; // move it to the top
  document.onmousemove = drag;
  document.onmouseup = drop;
  grabx = mousex;
  graby = mousey;
  elex = orix = dragobj.offsetLeft;
  eley = oriy = dragobj.offsetTop;
  update();
}

function drag(e) // parameter passing is important for NS family 
{

  if (dragobj)
  {
    elex = orix + (mousex-grabx);
    eley = oriy + (mousey-graby);
    dragobj.style.position = "absolute";
    dragobj.style.left = (elex).toString(10) + 'px';
    dragobj.style.top  = (eley).toString(10) + 'px';
  }
  update(e);
  return false; // in IE this prevents cascading of events, thus text selection is disabled
}

function drop()
{

  if (dragobj)
  {
/*
    var objdata = dragobj;
    dragobj.style.zIndex = 0;
    dragobj = null;

	var dropbox = document.getElementById('dropbox_content');
	var lastdrop = document.getElementById('lastdrop');
    if (elex > 250 && elex < 400 && eley > 200 && eley < 400) {
	    document.getElementById(objdata.id).style.display='none'; // hide on dropbox

	    if (dropbox.innerHTML == 'Drop Here...') dropbox.innerHTML = ''; // clear dropbox text if empty
	    var tmp = '<a href="##" class="ml" onclick="dropbox_remove(\''+objdata.id+'\'); this.style.display=\'none\';"><br>'+objdata.id+'&nbsp;[X]</a>';
	    dropbox.innerHTML = dropbox.innerHTML + tmp;
		lastdrop.innerHTML = 'DROP-BOX: ('+elex+':'+eley+')';
	} else {
		lastdrop.innerHTML = 'Last drop coords: ('+elex+':'+eley+')';
	}
	objdata = null; 
*/
  }

  update();
  document.onmousemove = update;
  document.onmouseup = null;
  document.onmousedown = null;   // re-enables text selection on NS
}

function dropbox_remove(target) {
	var trg = document.getElementById(target);
	trg.style.left='100px';
	trg.style.top='100px';
	trg.style.display='block';
}