private void username_txtbox_TextChanged(object sender, EventArgs e)
        {
            bool checkmail = Ismail.emailCheck(email_txtbox.Text);

            if (checkmail == true)
            {
                checkProvider.Visible = true;
                errorProvider.Visible = false;
                Send_btn.Enabled      = true;
            }
            else
            {
                errorProvider.Visible = true;
                checkProvider.Visible = false;
                Send_btn.Enabled      = false;
            }
        }
        private void Send_btn_Click(object sender, EventArgs e)
        {
            ProgressBar.StartProgress();
            bool   mailcheck;
            Ismail mail = new Ismail();

            if (SQL.checkEmailExists(email_txtbox.Text) == true)
            {
                mailcheck = mail.sendMail(email_txtbox.Text);
                if (mailcheck == true)
                {
                    errorProvider.Visible    = false;
                    checkProvider.Visible    = true;
                    email_send_check.Visible = true;
                    email_send_check.BringToFront();
                    email_send_error.Visible = false;
                }
                else
                {
                    errorProvider.Visible    = true;
                    checkProvider.Visible    = false;
                    email_send_error.Visible = true;
                    email_send_error.BringToFront();
                    email_send_check.Visible = false;
                    email_send_error.Text    = "Something is wrong try again late";
                }
            }
            else
            {
                errorProvider.Visible    = true;
                checkProvider.Visible    = false;
                email_send_error.Visible = true;
                email_send_error.BringToFront();
                email_send_check.Visible = false;
                email_send_error.Text    = "Email not exists";
            }
            ProgressBar.EndProgress();
        }