document.onmousemove = Dragging;
//document.onmouseup = StopDragging;
var varStartDrag = false;
var imageNum = 0; 
function Dragging(e){
	if(varStartDrag){
		var ev = e || window.event;
		var imgDrag =  $('imgDrag'+imageNum);
		imgDrag.style.visibility = "visible"; 
		imgDrag.style.position = 'absolute';
		imgDrag.style.zIndex = '200';
		//if not IE
		if(ev.pageX && ev.pageY)
		{
			imgDrag.style.top  = (parseInt(ev.pageY) + 5) + 'px';
			imgDrag.style.left = (parseInt(ev.pageX) + 5) + 'px';
		}
		else
		{
//			elem = document.documentElement;
            elem = document.body;
            imgDrag.style.top      = ev.clientY + elem.scrollTop  - elem.clientTop +5 ;        
            imgDrag.style.left     = ev.clientX + elem.scrollLeft - elem.clientLeft+20;
		}
	}
}
function StopDragging(e){
	ReleaseDragInfo();
	varStartDrag = false;
}
function StartDrag() { varStartDrag = true; }
function startPreview(num) {
    imageNum = num;
    StartDrag();
}
function stopPreview() { StopDragging('') }
function ReleaseDragInfo() {
      var imgDrag =  $('imgDrag'+imageNum);
	  if(imgDrag) {
        imgDrag.style.visibility = "hidden";
        imgDrag.style.zIndex = '-1';
         //if not IE
	    if(!document.all)
	    {
	  	    imgDrag.style.cssText += 'left:1px;top:1px;';
	    }
	    else
	    {
	 	    imgDrag.style.top      = 1;
	        imgDrag.style.left     = 1;
	    }
      }
}