I shall try the solution with jQuery, for sure it should give a nice result. Of course you have to load jQuery ... What about a pop-up with something like this? Of course this is dependant on the user authorizing pop-ups.
<html>
<head>
<script language="javascript">
var ret;
function returnfunction()
{
alert(ret);
}
</script>
</head>
<body>
<form>
<label id="QuestionToAsk" name="QuestionToAsk">Here is talked.</label><br />
<input type="button" value="Yes" name="yes" onClick="ret=true;returnfunction()" />
<input type="button" value="No" onClick="ret=false;returnfunction()" />
</form>
</body>
</html>