var objCount = 0; // number of (changing images on web-page 
   function preload(name, first, second) { 
   //preload images and place them in an array

   if (browserOK) {
	pics[objCount] = new Array(3); 
	pics[objCount][0] = new Image();
	pics[objCount][0].src = first;
	pics[objCount][1] = new Image;
	pics[objCount][1].src = second;
	pics[objCount][2] = name;
	objCount++;
	 }
   }

	function on(name){
	if (browserOK) {
	for (i = 0; i< objCount; i++) {
	if (document.images[pics[i][2]] != null)
	if (name != pics[i][2]) {
	//set back all other pictures
	document.images[pics[i][2]].src = pics[i][0].src;
	} else {
 	// show the second image because cursor moves across this image 
	document.images[pics[i][2]].src = pics[i][1 ].src;
	}
      }
     }
   }

   function off (){
    if (browserOK) {
    for (i = 0; i< objCount; i++){
    // set back all pictures
      if (document.images[pics[i][2]] != null)
     document.images[pics[i][2]].src = pics[i][0].src;
     }
    }
   }

   //==============================

   preload("link1", "picture/home.gif", "picture/home2.gif");
   preload("link2", "picture/product.gif", "picture/product2.gif");
   preload("link3", "picture/email.gif", "picture/email2.gif");
   preload("link4", "picture/client.gif", "picture/client2.gif");
   preload("link5", "picture/aboutus.gif", "picture/aboutus2.gif");