title: TextBox for mobile number validation in asp.net
body: <p>How can i customize a <code>RadRumeric TextBox</code> for mobile number validation. am using a <code>RadRumeric TextBox</code> for validating numbers. while using the same for mobile number validation it allows <code>.</code> how can i avoid this?</p>
  
  <pre><code> &lt;telerik:RadNumericTextBox ID="txtphone" Skin="WebBlue" runat="server" ValidationGroup="contact" Width="90%" MaxLength="32" NumberFormat-DecimalDigits="0"&gt;
             &lt;NumberFormat DecimalDigits="0" DecimalSeparator ="."/&gt;
   &lt;/telerik:RadNumericTextBox&gt;
   &lt;span class="warning"&gt;*&lt;/span&gt;&lt;br /&gt;
   &lt;asp:RequiredFieldValidator ID="RequiredFieldValidator25" runat="server" ControlToValidate="txtphone" CssClass="warning" ErrorMessage="Enter contact no." ValidationGroup="contact"&gt;&lt;/asp:RequiredFieldValidator&gt;
  </code></pre>
  
  <p>when i give <code>DecimalSeparator =""</code> will throws error</p>