title: excel vba - msgbox yes/no reply
body: <p>I'm validating users input in userform. I have a msgbox prompt, with yesNo.</p>
  
  <p>If yes is clicked then just continue, if no is clicked I want the user to be able to go back to the userform to change the input/selection.</p>
  
  <p>The code I've used is</p>
  
  <pre><code> iReply = MsgBox(Prompt:="You have selected a month which is not next month. Do you want to continue? ", _
       Buttons:=vbYesNo, Title:="")
       If iReply = vbNo Then
          UserForm.Show
       End If
  </code></pre>
  
  <p>I get an error for "form already displayed cannot show modally" for
      UserForm.Show</p>