protected void btnUpdate_Click(object sender, EventArgs e)
        {
            System.Text.StringBuilder sb = null;

            double hoursWorked;

            if (!Double.TryParse(txtEditHours.Text.Replace('.', ','), out hoursWorked) || hoursWorked <= 0)
            {
                this.lblEditErrorMessage.Text = "Valor das horas não é válido!";
                return;
            }


            if (string.IsNullOrWhiteSpace(txtEditComment.Text))
            {
                this.lblEditErrorMessage.Text = "É necessário informar um comentário!";
                return;
            }


            int      id       = Convert.ToInt32(HfUpdateID.Value);
            Activity activity = CurrentActivity();

            ActivityWorker activityWorker = activity.ActivityWorkers.Where(a => a.ID == id).SingleOrDefault();

            ActivityBusinessLogic activityBusinessLogic = new ActivityBusinessLogic();

            double maxHoursByDay = ActivityBusinessLogic.MaxWorkHoursByDay();

            double temp = activityWorker.Hours;

            activityWorker.Hours = hoursWorked;

            double hoursAvaiable = activityBusinessLogic.GetAvaiablesHoursByWorkerOnDate(activityWorker.Worker, activity.Date);


            if (hoursAvaiable < 0 || hoursWorked > maxHoursByDay || (hoursWorked - hoursAvaiable) > maxHoursByDay)
            {
                activityWorker.Hours          = temp;
                this.lblEditErrorMessage.Text = "As horas trabalhas superam as horas dispónives!";
                return;
            }

            activityWorker.Hours   = hoursWorked;
            activityWorker.Comment = txtEditComment.Text;


            ActivityWorkerBusinessLogic activityWorkerBusinessLogic = new ActivityWorkerBusinessLogic();

            activityWorkerBusinessLogic.Update(activityWorker);

            BindGridVeiwWorksByActivity();



            ScriptManager.RegisterClientScriptBlock(this,
                                                    this.GetType(),
                                                    "EditHideModalScript",
                                                    Util.GetScriptToHideModalDialog("editModal"),
                                                    false);



            this.txtEditDate.Text       = string.Empty;
            this.txtEditWorkername.Text = string.Empty;
        }