protected void btnCal2_Click(object sender, EventArgs e)
        {
            if (txtHeJi.Text == "")
            {
                return;
            }
            double   d        = Convert.ToDouble(txtHeJi.Text);
            MoneyCal moneyCal = new MoneyCal(d);

            txtCaiWuJE.Text = moneyCal.Convert();
        }
 protected void btnCal2_Click(object sender, EventArgs e)
 {
     if (txtHeJi.Text == "")
     {
         return;
     }
     double d = Convert.ToDouble(txtHeJi.Text);
     MoneyCal moneyCal = new MoneyCal(d);
     txtCaiWuJE.Text = moneyCal.Convert();
 }