imageArray = new Array();
current = "";
function load_img(name_src)
  {
   if(document.images) {
   var temp = imageArray[name_src];
   if(! temp) {
     temp = new Image();
     temp.src = name_src;
     imageArray[name_src] = temp;
     }
      return temp;
     }
  }
  
function replace_img(name, name_src)
  {
  if(document.images) {
    if(name != current) {
    document[name].src = load_img(name_src).src;
    }
    }
  }

load_img("/images/nav_home_on.gif");
load_img("/images/nav_contact_on.gif");
load_img("/images/nav_home_on.gif");
load_img("/images/nav_depaul_on.gif");
load_img("/images/nav_loyola_on.gif");
load_img("/images/nav_uc_on.gif");
load_img("/images/nav_uic_on.gif");

var imagenumber = 5 ;
var randomnumber = Math.random() ;
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1 ;
images = new Array
images[1] = "main-01.jpg"
images[2] = "main-02.jpg"
images[3] = "main-03.jpg"
images[4] = "main-04.jpg"
images[5] = "main-05.jpg"
var image = images[rand1]