//preload images
h4 = new Image();
h4.src = "images/head_04on.gif";
h5 = new Image();
h5.src = "images/head_05on.gif";
h6 = new Image();
h6.src = "images/head_06on.gif";
h7 = new Image();
h7.src = "images/head_07on.gif";
//ends