setting different resolutions for different displays?, setting different resolutions for different displays?

Hi,

I have a 30" dell display that I have used with my MBP. I recently got a MBA and installed mountain lion. One of the things they inexplicably removed was the ability in the menu bar to set different resolutions for different displays. The only way I can get my Dell Monitor to work is to use mirroring. But I don't want mirroring. I want two separate displays. In Snow Leopard, the drop down display menu in the menu bar allowed you to pick different resolutions for different displays. Is there any possible way to do that in Mountain Lion?

Tom