My mother-in-law, who lives overseas, bought an external monitor for her MacBook White. I helped her with screensharing and video chats to set it up that it shows the same picture as on the MacBook when both are on (mirrored). I showed her how she can use her external monitor while having the MacBook lid closed (close the lid of the MacBook, have the power cord connected and press any key on the external keyboard to wake up the MacBook). So far, this works fine. The problem now is, when she works on the external monitor with the MacBook lid closed and then opens the lid of the MacBook to do a video chat using the iSight of the MacBook, her MacBook screen stays blank. It only turns on when she puts her MacBook asleep and wakes it up by opening up the MacBook lid. Here is my question: How can she get her MacBook screen activated when only the external monitor is on, without going through putting it to sleep first and waking it up again?