<script language="JavaScript">
function vc(id) {
var obj = document.getElementById(id)
if(obj.style.display == "none")
   obj.style.display = "block"
else
   obj.style.display = "none"
}
</script>
<table align="center" border="1">
<tr><td><a onClick="vc('abc');">click</a></td></tr>
<tr><td id="abc">abc</td></tr>
<tr><td><a onClick="vc('abc2');">click</a></td></tr>
<tr id="abc2"><td>abc2</td></tr>
</table>