Mac Forums

I bought a 23 inch external monitor. When I operate my MacBook Pro and the monitor in the dual monitor function, the Macbook keeps it's normal resolution, and the external monitor has a much greater resolution. I only want to use the external monitor, when I choose "mirror displays", it reduces the resolution on the larger monitor to the resolution of the laptop. My question is, how can I turn off dual monitor function and keep the awesome high resolution of the 23 inch monitor?

Thanks!