Help Me!

[Crysis]

So I was putting my old radio in because my cd player was stolen last week and now somehow my car wont unlock!!! I disconnected the battery to install the cd player and once I was finished I reconnectred it and shut the hood...tested the radio and it worked so I shut my doors to go inside and when I came back out.....my car wont unlock! My remote will only lock it and I had to replace my doors because of the robbery and I didnt get a chance to switch out the locks. Is there any way of getting in? I can open my trunk, byut i cant find a way to open the back seats. Why would my car only lock itself? Any suggestions? It would be best to not call a locksmith...since Im a poor college kid