>Integers are passed by value (I'm assuming lnLeft/lnTop *are* integers) so something else must be going on.
>e.g:

                 var i = 5;
>                  oDiv.onmouseout = function(e) {
>                      OnMouseOut(e, i);
>                      alert("After"+i); // 5
>                  };
>                  
> 
>                  function OnMouseOut(e, i) {
>                      i = i + 1;
>                  }

Yes, I would adjust to use the var declaration approach instead.