// Preload image - incase they are large images.
if(document.images){
  var main = new Image(); main.src = "../images/message.jpg";
  var img1 = new Image(); img1.src = "../images/messagesandra.jpg";
  var img2 = new Image(); img2.src = "../images/messagedan.jpg";

}

function change(imageName){
  if(document.images){ document['main'].src = eval(imageName + ".src"); }
}

function changeBack(){
  if(document.images){ document['main'].src = main.src; }
}