camera limits in level creator

[asnooob]

[AS3] Hi, I´m working on a platformer. Right now I have a problem with the camera on the level creator. It works like this: the camera has the dimension of the stage and it masks the whole level. You control it with WASD to move around the level. What I want is that it cant go too far away from the level. Seems pretty simple but I cant get it to work properly, because when i modify the level edges, the camera bugs out and it escapes the level and it doesn't come back, even if you try to move it to the level direction. Any help?