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 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
      mousex = e.clientX + document.body.scrollLeft;
      mousey = e.clientY + document.body.scrollTop;
      algor = '[e.clientX]';
      if (e.pageX || e.pageY) algor += ' [e.pageX] '
    }  
  }

}


function grab(context)
{
  getMouseXY()
  
  document.onmousedown = falsefunc; // in NS this prevents cascading of events, thus disabling text selection
  dragobj = context;
  dragobj.style.zIndex = 100; // move it to the top
  document.onmousemove = drag;
  document.onmouseup = drdrop;
  grabx = mousex;
  graby = mousey;
  elex = orix = dragobj.offsetLeft;
  eley = oriy = dragobj.offsetTop;
	

}

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

    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';
	
  }
	
  return false; 
}

function drdrop()
{
  if (dragobj)
  {
    top.lastLeft = dragobj.style.left;
    top.lastTop = dragobj.style.top;
    dragobj.style.zIndex = 100;
    dragobj = null;
  }


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