Dell UltraSharp 1908WFP Monitor

I bought the 1908wfp to use it as a second monitor having as monitor1 a 1708fp, but I couldn't configure both together, the color, brightness and contrast were awful in the 1908wfp.
I contacted dell support, they made a remote control on my desktop, and was the same.
If you´re planning to use a 17" and 19" together, I wouldn´t recommend it.
To work with 2 monitors, you'll get a better performance if both are the same size (brand, model etc).