Read the article below. Has everything u need to know. Thats just a small insert click the link for the rest.
http://www.tweakheadz.com/dual_monitor_ ... r_DAW.html
"With your dual video card configured, the right edge of your screen becomes the right edge of monitor #2. The left edge, naturally, remains the left edge of monitor#1. If you run both monitors at the same resolution, you will have a continuous workspace from one monitor to the next. But it is not necessary to run both at the same resolution. My main monitor is at 1280 X 1024, while my second monitor runs at 1024x768. In my case the top edge is aligned across both screens, and I can't view the bottom right of the large rectangle. It's not a problem though. I just don't put anything down there. Because I use logic, i can save my screensets to match this expanded workspace perfectly. Yes, when you save a screenset, it saves the entire workspace for both monitors. Heh, this has dramatically improved my sequencing. Typically, I will devote all of monitor 2 to the Logic Mixer and all of monitor 1 for a really big arrange screen. Yet there are many ways to work that open up. "