private void PictureBox1_Click(object sender, EventArgs e)
        {
            Boolean isOpen = false;

            foreach (Form f in Application.OpenForms)
            {
                if (f.Text == "Manage Employees")
                {
                    isOpen = true;
                    f.BringToFront();
                    break;
                }
            }

            if (!isOpen)
            {
                FormManageEmployees f = new FormManageEmployees(UserID, this);
                f.Show();
            }
        }