intImage = 2;
function swapImage() {
switch (intImage) {
 case 1:
   document.getElementById('PresentFuture').src = "images/PresentVision.gif";
   intImage = 2;
   return(false);
 case 2:
   document.getElementById('PresentFuture').src = "images/FutureVision.gif";
   intImage = 1;
   return(false);
 }
}