private void RemoveAllLocks_Click(object sender, EventArgs e)
        {
            if (sender is ToolStripMenuItem)
            {
                ToolStripMenuItem          tsi   = (ToolStripMenuItem)sender;
                ScanButtonContextMenuStrip pbcms = (ScanButtonContextMenuStrip)tsi.GetCurrentParent();
                IntPtr    pointer = pbcms.tableHandle;
                TableData td      = TableHandler.tableSessions[pointer];

                // Unlock in TableData
                td.unlockAllSeats();

                // Unlock buttons => remove lock icons
                string tablename        = td.tablename;
                PlayerButtonHandler pbh = TableHandler.buttonInventory[tablename];
                pbh.removeAllLockImages();
            }
            else
            {
                throw new Exception("Sender is no ToolStripMenuItem!");
            }
        }