// Open Employee form.
        // To Create.
        private void Button3_Click(object sender, EventArgs e)
        {
            foreach (Form f in Application.OpenForms)
            {
                if (f is F300_Employee)
                {
                    f.Focus();
                    return;
                }
            }
            F300_Employee f300 = new F300_Employee();

            f300.EmployeeRefresh += RefreshRequest;
            f300.Show();
        }
 // To Edit.
 private void UpdateEmployeeButton_Click(object sender, EventArgs e)
 {
     foreach (Form f in Application.OpenForms)
     {
         if (f is F300_Employee)
         {
             f.Focus();
             return;
         }
     }
     if (mainData.CurrentRow != null)
     {
         F300_Employee f300 = new F300_Employee(this.EmployeeID);
         f300.EmployeeRefresh += RefreshRequest;
         f300.Show();
     }
     else
     {
         MessageBox.Show(RowSelectMessage);
     }
 }