Linksys connection on two laptops

Hello,
I have used this linksys router before and everything worked fine. I moved and now have a roommate who has a laptop too. My laptop wont connect to the internet without the ethernet cord connected to the modem (refuses wireless at home) My roomate can use my router just fine without being physically connected. How do I get my computer to recognize the router as well like before? Having to constantly plug and unplug the cord and switch between wireless and using the cable causes my computers to only stay on the internet for a short while! please help! were both students and don't have time to schedule internet time.