在线求：根据不同时间显示表格中背景图片的JS代码！！！

楼主可以自己再调试<script type="text/javascript" language="javascript">

function showIt()
{
self.setInterval('showrand()',1000);
} function showrand()
{
var srcs = "./image/image";
var img = document.getElementById("imgs");
var mytable = document.getElementById("mytable");
var rd = Math.random();
var rdd = Math.round(rd*10);
var no = 0;
if (rdd <1 )
{
no = 1;
}
else if ( rdd > 4 )
{
no = 4;
}
else
{
no = rdd;
}
img.src = srcs+no+".gif";
mytable.setAttribute("className","c"+no);
}</script>
<style type="text/css">
.c1{
background-image: url("./image/image1.gif");
}
.c2{
background-image: url("./image/image2.gif");
}
.c3{
background-image: url("./image/image3.gif");
}
.c4{
background-image: url("./image/image4.gif");
}
</style>
</HEAD><BODY onload="showIt();">
<button onclick="showrand();">shows</button><br>
<button onclick="self.clearInterval();">stop</button><br>
<img id="imgs" src="./image/image1.gif">
<TABLE id="mytable" name="mytable" width="60%" height=60%  border=1 cellpadding="0" align="center" background="./image/image1.gif">
<TR>
<TD>1</TD>
<TD>1</TD>
</TR>
<TR>
<TD>1</TD>
<TD>1</TD>
</TR>
</TABLE>
</BODY>
</HTML>