hp_banner = new Array () ;

hp_banner[0] = "<a href=\"/articles/view/2372\" onClick=\"javascript:urchinTracker(\'/outgoing/banner/JMEagle\');\"><img src=\"http://www.earth.columbia.edu/sitefiles/image/home/banners/JMEagle_09.jpg\" alt=\"Cleaner, Safer Water \" border=\"0\" /></a>";
//hp_banner[1] = "<a href=\"http://www.earth.columbia.edu/articles/view/2362\" onClick=\"javascript:urchinTracker(\'/outgoing/banner/Water\');\"><img src=\"http://www.earth.columbia.edu/sitefiles/image/home/banners/Spotlight-Water.jpg\" alt=\"Water Center\" border=\"0\" width=\"678\" height=\"222\" /></a>";

function random_num (){ 
                var rand = Math.floor ( ( Math.random ( ) *1) ) ;              
                return rand;    
}

val = random_num();