var ic = 4; 
var img = new Array(ic); 
img[0] = "1"; 
img[1] = "2"; 
img[2] = "3"; 
img[3] = "4"; 
function pickRandom(range) 
{ if (Math.random) return Math.round(Math.random() * (range-1)); else { var now 
= new Date(); return (now.getTime() / 1000) % range; } } 
var choice = pickRandom(ic);