preventing non-ints in a string

[CPCericola]

In your validation code(KeyPress or KeyDown), do the following:

private void textBox1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
{
  if ((Char.IsDigit(e.KeyChar) == false) && (Char.IsControl(e.KeyChar) == false))
  {
    e.Handled = true;
  }
}

That chesk for digits(0-9) and control keys(arrows, delete, etc). Hope that helps!