private void SalaryReportForm_Load(object sender, EventArgs e)
        {
            SalaryService SalService = new SalaryService();

            dataGridView1.DataSource = SalService.GetAllCategories();
        }
        void UpdateGridView()
        {
            SalaryService SalService = new SalaryService();

            dataGridView1.DataSource = SalService.GetAllCategories();
        }