Working with an external screen

[MBP*]

I just hooked up my Dell 21" screen via DVI

I basically want to be able to plug in this and close the lid of my MBP and continue using the screen via the bluetooth keyboard and mouse. However, everytime I do that, the external screen goes into power save mode and turns off. It's making me leave my laptop screen on.

 

[glenthompson]

Is the MBP plugged into power? If not, it goes into sleep mode.

 

[Altemose]

I just hooked up my Dell 21" screen via DVI

I basically want to be able to plug in this and close the lid of my MBP and continue using the screen via the bluetooth keyboard and mouse. However, everytime I do that, the external screen goes into power save mode and turns off. It's making me leave my laptop screen on.

http://support.apple.com/kb/ht3131

That should be of some use...