title: Enter numeric value only into textbox in visual basic
body: <p>I am trying to set up a form to accept a telephone number, but i am unsure of how to validate it so it will only take numeric values with 11 digits.</p>
  
  <p>So far i have it working to ensure that there is something in the textbox</p>
  
  <pre><code> 'Validate data for Telephone Number
   If txtTelephoneNumber.Text = "" Then
   txtTelephoneNumber.Focus()
   MessageBox.Show("You must enter a Telephone Number.", "Data Entry Error", MessageBoxButtons.OK, MessageBoxIcon.Information)
  </code></pre>