2000 Chrysler Town and Country transmission

I took the battery out to have it checked. I than put the battery back in and started the van. I went to put it in reverse and the gear shifter would slide up and down the column without moving into an actual gear. Shut the van off and the key won't go all the way back so I can't get the key out of it. There wasn't any signs of problems before taking out the battery. I see that is has an electronic transaxle and read something about maybe having to have it reset. Just wondering what if could be because I have taking out many batteries before and never had a problem like this. Thanks