Random Image
这准备了四种图案，每次刷新结果不一定相同。
<![CDATA[把以下代码放在<head></head>之间：]]>
<![CDATA[
<script language="JavaScript">
a = 4
var slump = Math.random();
var talet = Math.round(slump * (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 = "reset.gif"
b[1].border = "0"
b[1].alt = "111"
b[2].src = "back.gif"
b[2].border = "0"
b[2].alt = "222"
b[3].src = "ie.gif"
b[3].border = "0"
b[3].alt = "333"
b[4].src = "netscape.gif"
b[4].border = "0"
b[4].alt = "444"
var visa = "";
visa += '<img src='+b[talet].src+' border="0"'+' alt='+b[talet].alt+'>';
</SCRIPT>
]]>
<![CDATA[把以下代码放在HTML文件任意地方：]]>
<![CDATA[
<script language="JavaScript">
<!-- Hide this script from old browsers --
document.write(visa)
// -->
</script>
]]>