My girlfriend left a cup in my cupholder over the weekend.  Apparently it was some sort of pop and it leaked down into the stereo and gummed up the buttons. 

   The 0 key will not work and I need it to put the security code in after cleaning up the mess.  Is there anything I can do now?  Or is this just a lost cause?
I don't think the problem is with the button itself because, I popped it off and used a small dowel to try and push the button and nothing happens.  I believe it's with the connection from the face plate to the stereo.  BTW, it's a CDR220.