<!--
var xPos = 100;                                                                  
var yPos = document.body.clientHeight;                                                                  
var step = 1;                                                                  
var delay = 40;                                                                   
var height = 0;                                                                 
var Hoffset = 0;                                                                 
var Woffset = 0;                                                                 
var yon = 0;                                                                 
var xon = 0;                                                                  
var pause = true;                                                                  
var interval;                                              
document.getElementById('imgGD').style.top = yPos; 

function changePos() {                                                                  
width = document.body.clientWidth;                                                                  
height = document.body.clientHeight;                                                                  
Hoffset = document.getElementById('imgGD').offsetHeight;                                                                  
Woffset = document.getElementById('imgGD').offsetWidth;                                                                  
document.getElementById('imgGD').style.left = xPos + document.body.scrollLeft;                                                                  
document.getElementById('imgGD').style.top = yPos + document.body.scrollTop;                                                                  
if (yon) {                                                                  
yPos = yPos + step;                                                                  
}                                                                  
else {                                                                  
yPos = yPos - step;                                                                  
}                                                                  
if (yPos < 0) {                                                                  
yon = 1;                                                                  
yPos = 0;                                                                  
}                                                                  
if (yPos >= (height - Hoffset)) {                                                                  
yon = 0;                                                                  
yPos = (height - Hoffset);                                                                  
}                                                                  
if (xon) {                                                                  
xPos = xPos + step;                                                                  
}                                                                  
else {                                                                  
xPos = xPos - step;                                                                  
}                                                                  
if (xPos < 0) {                                                                  
xon = 1;                                                                  
xPos = 0;                                                                  
}                                                                  
if (xPos >= (width - Woffset)) {                                                                  
xon = 0;                                                                  
xPos = (width - Woffset);                                                                  
   }                                                                  
}                                                                  
function start() {                                                                  
document.getElementById('imgGD').visibility = "visible";                                                                  
interval = setInterval('changePos()', delay);                                                                  
}                                                                  
start();  
-->