随机出现图片:

直接放到网页的页面中就行了!

<script language="javascript">
a = 3
var pp = Math.random();
var foot = Math.round(pp * (a-1))+1;
function create() {
        this.src = ''
        this.border = ''
 this.alt = '' 
}
b = new Array()
for(var i=1; i<=a; i++) { b[i] = new create() }
b[1].src    = "img/4.jpg"
b[1].border = "0"
b[1].alt    = ""
b[2].src    = "img/2.jpg"
b[2].border = "0"
b[2].alt    = ""
b[3].src    = "img/3.jpg"
b[3].border = "0"
b[3].alt    = ""
var pic = "";
pic += '<img src='+b[foot].src+' border="0"'+' alt='+b[foot].alt+'>';
document.write(pic)
</script>