Prefetch Images II
Once the array is declared and setup,
get the images and assign them to
the .src field of the array:
for (i=0; i<4; i++) {
     pref [i].src = "new" + i + ".gif";
}
Notice that the names of the images,
new0.gif, new1.gif, new2.gif, new3.gif
are “constructed” using the index variable