Hover your cursor over the black box and press 'Z'.
Then you can move around like you would in 'NoClip mode' in-game. (Mouse to look around and W,S,A,D to move.
Hope that helps.
Oh and use the edit button, don't double post.
![:)](http://192.241.182.11/images/smilies/smile.png)
Oh and this should go in 'HL Engine Discussion'