How to Validate only Numbers in Textbox

To validate only numbers in text box.

Step 1: Desing a Textbox in asp.net .

Step 2 : Goto Coding side of the page .

Step 3: Post the following coding

<asp:regularexpressionvalidator controltovalidate="TextBox9" errormessage="Please Enter Numbers Only " id="RegularExpressionValidator2" runat="server" validationexpression="^\d+$" validationgroup="check"></asp:regularexpressionvalidator>