alt = new Array;
alt[1] = "Hinhanh vienzu";

var rand1 = 0;
var useRand = 0;

function SwapImage() {
var imgnum = 4642;
{
var randnum = Math.random();
rand1 = Math.round((imgnum - 1) * randnum) + 1;
} 
useRand = rand1;
document.write('<img width="100%" alt="' +  alt[1] + '" src="/images/vienzu/vz' + useRand + '.jpg" height="300" border="0">');
}