Game Play Resolution

In my game I am developing i have a Computer Screen. I have a Camera that is pointing at it. they was I have it set up now is. Camera pints at the 3d Computer Screen.

Currently I am in :Free Aspect: Under the Game Tab.

How can I set my resolution for my camera for ex: in after affects and maya, you can set you resolution and title safe.
How to I need to set up my camera in Unity so when I build my Game, The game will have 1 or 2 resolutions to chose from. ???

Help needed.

On the game view there should be a drop-down menu to set the editor scene to a certain resolution