Allow entering only numeric values using jquery in asp.net

Jquery

<script type="text/javascript">
        var specialKeys = new Array();
        specialKeys.push(8);                       //Backspace

        jQuery(document).ready(function () {
            $(".numeric").bind("keypress", function (e) {
                var keyCode = e.which ? e.which : e.keyCode
                var ret = ((keyCode >= 48 && keyCode <= 57) || specialKeys.indexOf(keyCode) != -1);
                $(".intervalError").css("display", ret ? "none" : "inline");
                return ret;
            });
            $(".numeric").bind("paste", function (e) {
                return false;
            });
            $(".numeric").bind("drop", function (e) {
                return false;
            });
        });
    </script>

 .Aspx Web Form

//Textbox for Entering Age (allowing only numeric values to enter here)
 <div>
<asp:TextBox CssClass="numeric" ID="txtAge" runat="server" />
</div>