title: Test if the user typed email format ASP.NET (VB)
body: <p>I have a <code>TextBox</code>, and I want to force the user to type an email format in this field like (example@mail.com) ?</p>
  
  <p>I don't want to use <code>FilteredTextBoxExtender</code> or the <code>RegularExpressionValidator</code>. </p>
  
  <p>I want to do it <code>manualy</code>.</p>