private void TSensitivity_MouseDown(object sender, MouseEventArgs e)
{
TSensitivity.Select(TSensitivity.Text.Length, 0);
}
private void TSensitivity_MouseMove(object sender, MouseEventArgs e)
{
(sender as TextBox).SelectionLength = 0;
TSensitivity.Select(TSensitivity.Text.Length, 0);
}