Latitude E6400 - network cables vs. wifi

Hello...this is my first post, so here goes:

For some reason recently, whenever I plug in a network cable, browsing is immediately directed to that instead of the wifi. Sometimes I need to connect to both wired and wireless networks concurrently but this means that I lose my internet connection which is on the wifi but not the wired. How can I fix this? I know that on the Inspirons that I've used previously this is a setting in the network card configuration, but it strangely isn't for the Latitude.

How can I keep my browser connecting through wifi when I plug in my wired network? The wifi itself isn't disabled, it is still on and connected, but the browser (all 3 browsers I have installed) immediately ignore the wifi and try to access the internet via wired.

Thanks for any help!

Bashar