private void button1_Click(object sender, EventArgs e)
 {
     try
     {
         ChangePasswordCtrl.showquestion(textBox2, textBox1.Text);
     }
     catch (Exception err)
     {
         MessageBox.Show("您输入账号有误", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
     }
 }
 private void button3_Click(object sender, EventArgs e)
 {
     if (textBox3.Text.Trim() == ChangePasswordCtrl.answer(textBox1.Text).Trim())
     {
         label4.Visible   = true;
         textBox4.Visible = true;
     }
     else
     {
         MessageBox.Show("您输入的答案不正确!");
     }
 }
 private void button2_Click(object sender, EventArgs e)
 {
     ChangePasswordCtrl.change(textBox4.Text, textBox1.Text.Trim());
     MessageBox.Show("密码修改成功", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
     this.Close();
 }