Monitor Help

[rhino9907]

So today I purchased a 19" Widescreen Samsung monitor to hook up to my laptop. I actually have two laptops, one is a Dell Inspiron E1405 which is my primary one, the other is a Gateway that I rarely ever use. Anyway, I got the monitor hooked up adn working, but its set to work with a dual monitor mode. Because of that, it takes the size of my laptop and resizes everything on the other monitor to fit the laptop. I.E. Poker tables. This means that I have the same overlap on 4 tables with the 19" monitor as I do with a 14" monitor on my laptop. How the heck can I fix this problem? Ive tried to make it where my big monitor is the primary monitor but thats not working it doesnt seem like. If I could do that on the Gateway, where the only monitor that works is the big one, I would essentially just use that one as a desktop, so if anyone knows how that works let me know too.

Thanks!