Yes you could use string.ToUpper() from the textbox leave event.
I gave Richard two other solutions in a different thread related to the same thing:

private void textBox1_TextChanged(object sender, EventArgs e)
{
  ((TextBox)sender).Text = ((TextBox)sender).Text.ToUpper();
  ((TextBox)sender).SelectionStart = ((TextBox)sender).Text.Length;
}

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
  if (char.IsLetter(e.KeyChar) && !char.IsUpper(e.KeyChar))
  {
    e.KeyChar = char.ToUpper(e.KeyChar);
  }
}

>What about String.ToUpper()?
>
>
>
>>I don't think CharacterCasing is available in the compact framework.
>>
>>>Hi Richard!
>>>
>>>Textboxes do have a property called CharacterCasing which can be set to 'Normal', 'Upper' and 'Lower'.
>>>
>>>HTH
>>>
>>>>I want to ensure that all my character inputs are shown as UPPER case on input. I am converting then to upper on RETURN.
>>>>
>>>>NEEDS TO BE DONE PROGRAMMATICALLY WITHOUT A METHOD AS ITS POCKET PC
>>>>
>>>>Regards
>>>>
>>>>Richard