private bool checkValid() { bool isError = false; bool ActivityisError = false; String ActivityErrors = ""; String ErrorMessage = ""; ActivityRegistrationDetailUC1.CheckValid(out ActivityisError, out ActivityErrors); ErrorMessage += ActivityErrors; if (ActivityisError) { isError = ActivityisError; } ActivityRegistrationDescriptionUC1.CheckValid(out ActivityisError, out ActivityErrors); ErrorMessage += ActivityErrors; if (ActivityisError) { isError = ActivityisError; } ActivityRegistrationTimetableUC1.CheckValid(out ActivityisError, out ActivityErrors); ErrorMessage += ActivityErrors; if (ActivityisError) { isError = ActivityisError; } activityregistrationgroup1.CheckValid(out ActivityisError, out ActivityErrors); ErrorMessage += ActivityErrors; if (ActivityisError) { isError = ActivityisError; } lblError.Text = ErrorMessage; return(isError); }