Allowing only Numbers and Backspace in a Text Box in Windows Application

private void txt_policy_version_KeyPress(object sender, KeyPressEventArgs e)	
{ 
   if((e.KeyChar < '0' || e.KeyChar > '9') && (e.KeyChar != '\b'))
   {	
      MessageBox.Show("Only Numbers are Allowed");
      e.Handled = true;
   }
   else
   {
      e.Handled = false;
   }
}