var loaded_images = new Array()
var preloaded_images = new Array();
function preload_images() {
    loaded_images = new Array()
    if (document.images) {
        for(var i = 0; i < preloaded_images.length; i++) {
            loaded_images[i] = new Image()
            pic1on= new Image(100,25);
            loaded_images[i].src = preloaded_images[i];
        }
    }
}
function add_preload(path) {
    var pi_length = preloaded_images.length
   preloaded_images[pi_length] = path
}

// To add a new image to the preload list simply do
//   var pi_length = preloaded_images.length
//   preloaded_images[pi_length] = 'path/to/image.gif'
SafeAddOnload(preload_images)