private void button2_Click(object sender, EventArgs e) { regex = new Regex(@"^[0-9]{6}$"); string code = textBox9.Text; Match match = regex.Match(code); if (!match.Success) { if (code.Length == 6) { label27.Text = "Enter digits only"; label27.ForeColor = System.Drawing.Color.Red; } else { label27.Text = "Please enter OTP code."; label27.ForeColor = System.Drawing.Color.Red; } } else { ClientRegistrationService.UserOtpVerification userOtpVerification = new ClientRegistrationService.UserOtpVerification() { OneTimePasswordforVerification = Int32.Parse(code), User_Email_Address = emailAddress }; //userOtpVerification.OneTimePasswordforVerification,userOtpVerification.User_Email_Address //Int32.Parse(code),emailAddress //ClientRegistrationService.OTP_Verified otpVerified = clientRegistration.verifyUser(userOtpVerification.OneTimePasswordforVerification,userOtpVerification.User_Email_Address); Boolean result = clientRegistration.verifyUser(userOtpVerification.OneTimePasswordforVerification, userOtpVerification.User_Email_Address); if (result) { this.Hide(); login l1 = new login(); l1.Show(); } else { label27.Text = "Invalid OTP code"; label27.ForeColor = System.Drawing.Color.Red; } } }