hiii
Im My case I use a TextBox (Text1),On the onclick event it checks the Text1
is null or not with the help of js
<html>
<head>
<script type="text/javascript">
function show()
{
var a=document.getElementById("Text1").value;
if(a=="")
{
alert('Please enter some values in it');
}
}
</script>
</head>
<body>
<input type="text" id="Text1" onclick="show()" />
</body>
</html>