function bgchange(){
 var lis= document.getelementbyid("album_ul").getelementsbytagname('li');
 for(var i=1; i<lis.length; i+=2)
 lis[i].style.background = 'url(images/news_icons.jpg) 21px center no-repeat #e4e4e4';
}
window.onload = bgchange;