public void setCmbSemester()
        {
            systemManager objsystemManager = new systemManager();

            cmbSemster.DataSource    = objsystemManager.GetSemeDatatoStuSemAllocation();
            cmbSemster.ValueMember   = "SemesterID";
            cmbSemster.DisplayMember = "SemesterCode";

            //because of this department combo's display inedex will shown as a blank index
            cmbSemster.SelectedIndex = -1;
        }