private void button1_Click(object sender, EventArgs e)
{
double number = Convert.ToDouble(txtAmount.Text);
try
{
if (number < 0)
{
throw new NegativeNumberException();
}
}
catch (NegativeNumberException error)
{
MessageBox.Show(error.Message);
}
English english = new English(number);
if (number >= 0)
label3.Text = english.Converter();
}