var img_name = new Array(["../images/Top-Ad.who-igm.257x92.png", "http://www.ifpma.org/Influenza/WHOIGM"]);
function get(id) {
	return document.all?document.all[id]:document.getElementById(id)
}
function choose() {
var l = img_name.length;
var rnd_no = Math.floor(l*Math.random());
get("randomimage").src = img_name[rnd_no][0];
get("anchor").href = img_name[rnd_no][1];
}