a = 3 // a=numbers of banners
var slump = Math.random();
var talet = Math.round(slump * (a-1))+1;
function create() {

this.src = ''
this.href = ''
this.alt = ''
this.under = ''
}

b = new Array()
for(var i=1; i<=a; i++) { b[i] = new create() }

b[1].src = "images/zhutitu/yangguang.jpg"
b[1].href = "service/default.html"
b[1].alt = "联想阳光服务"

b[2].src = "images/zhutitu/wuxianzy.jpg"
b[2].href = "huodong/legend"
b[2].alt = "联想无限自由"

b[3].src = "images/zhutitu/shouji-zhuti.jpg"
b[3].href = "product/shouji/shouji.html"
b[3].alt = "联想手机"