Number only Textbox C#

hi friends this is the code for preventing the textbox to accept other than numbers

private void txtAccount_KeyPress(object sender, KeyPressEventArgs e)

        {

            TextBox txt = (TextBox)sender;

            if (((int)e.KeyChar >= 48 && (int)e.KeyChar <= 57) || ((int)e.KeyChar == 8))

            {

                e.KeyChar = e.KeyChar;

            }

            else

            {

                e.KeyChar = Convert.ToChar(0);

            }

            if (txt.Text.Length - txt.SelectedText.Length >= 9 && ((int)e.KeyChar != 8))

            {

                e.KeyChar = Convert.ToChar(0);

            }

        }