private void purchaseReportButton_Click(object sender, EventArgs e)
        {
            purchaseActivePanel.Show();
            salesActivePanel.Hide();

            PurchaseReportUiController purchaseReportUiController = new PurchaseReportUiController();

            mainPanel.Controls.Clear();
            purchaseReportUiController.Dock = DockStyle.Fill;
            purchaseReportUiController.BringToFront();
            purchaseReportUiController.Focus();
            mainPanel.Controls.Add(purchaseReportUiController);
        }
        public ReportUiController()
        {
            InitializeComponent();

            purchaseActivePanel.Show();
            salesActivePanel.Hide();

            PurchaseReportUiController purchaseReportUiController = new PurchaseReportUiController();

            mainPanel.Controls.Clear();
            purchaseReportUiController.Dock = DockStyle.Fill;
            purchaseReportUiController.BringToFront();
            purchaseReportUiController.Focus();
            mainPanel.Controls.Add(purchaseReportUiController);
        }