jmpImg = new Array();

jmpImg[0]="<a href=''><img src='' alt='' /></a>";

jmpImg[1]="<a href=''><img src='' alt='' /></a>";

function raImg() {
var rr = parseInt(Math.random()*jmpImg.length);
document.write(jmpImg.slice(rr,rr+1)[0]);
jmpImg.splice(rr,1);
}