<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<script>
function uncheck(obj)
{
var radio=obj;
if (radio.tag==1)
{
radio.checked=false;
radio.tag=0;
}
else
{
radio.checked=true;
radio.tag=1
}
}
</script>
<BODY>
<input type="radio" id="rad" name="abc" onclick="uncheck(this);"/>
</BODY>
</HTML>