var thumb = null;
function showThumbnail(which,e){
    thumb = document.getElementById('thumb');
    if( thumb && thumb.style.visibility == 'hidden' ){
        thumb.style.left       = e.pageX ? pageXOffset + e.clientX + 20 : document.body.scrollLeft + e.x + 20;
        thumb.style.top        = e.pageY ? pageYOffset + e.clientY : document.body.scrollTop  + e.y;
        thumb.style.visibility = 'visible';
        thumb.innerHTML        = '<img src="' + which + '">';
    }
}

function closeThumbnail(){
    if( thumb )
        thumb.style.visibility = 'hidden';
}