title: Clear required/not null bound textbox
body: <p>I have a problem with a bound textbox. The field is <strong>required</strong> and don't allow <strong>Null</strong> in the database.</p>
  
  <p>This gives me a problem when I want to clear the textbox. For example if I entered something and deleted it then the validation rule kicks in and don't allow me to leave the field. I can only leave the field if I hit ESC so reset it to its original (unaltered) state.</p>
  
  <p>I tried setting the field to <code>Nothing</code> and <code>DefaultValue</code> in an <code>_After-/_BeforeUpdate()</code>  event but that doesn't work.</p>
  
  <p><em>Thank you for your help.</em></p>