This example demonstrate you that how to use jQuery.isNumeric method with asp.net. jQuery.isNumeric() is new in jQuery 1.7. You can download jQuery 1.7 from here. I have added Microsoft CDN reference on this example. You can get the jQuery reference from Google, Microsoft and jQuery CDN.

Microsoft CDN
http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.7.min.js
Syntax
jQuery.isNumeric ()
Returns true if its input is a numeric value and if input is not numeric then returns false.
Here’s an example
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>jQuery.isNumeric ()</title>
<script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.7.min.js"></script>
<script type="text/javascript">
$(function () {
$("#<%= Button1.ClientID %>").click(function (ev) {
var isnumber = $.isNumeric($("#<%= TextBox1.ClientID %>").val());
alert(isnumber);
ev.preventDefault();
});
});
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<p>
Input: <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Click"></asp:Button>
</p>
</div>
</form>
</body>
</html>
Note: JQuery.isNumeric method return true for octal, hex number, float, negative and positive number and exponential number.
Output

Download
jQuery-isNumeric.rar (905.00 bytes)
See live demo