My horizontal sliding window has no locks and both panels slide freely on its individual tracks (so the window can be opened from both the left and the right). Usually, only one of the panels move for these kind of windows and all you have to do is put a stick on the interior side of the sliding track and the window can't be opened. But both panels of my window can slide to open, is there a way I can lock it w/out installing a lock? how do I do it?