xx = 0;

imagex = 0;
imagey = 0;

function followImage (id,event,xoffset,yoffset) {
    
    var x = mouseX(event)+xoffset;
    var y = mouseY(event)+yoffset;
   
    imagex = x;
    imagey = y;
 
    if (!xx) xx = window.setTimeout("moveImage(\""+id+"\")",10);
}

function moveImage (id,x,y) {
    document.getElementById(id).style.top  = imagey + "px"; 
    document.getElementById(id).style.left = imagex + "px";
    xx = 0;
}