If my remote suddenly stops working do I need a battery?

My remote worked fine this morning and tonight it's not working at all. I found the directions to reprogram it but do I need to replace a battery or something first?

Any help appriciated.

Wife of BigWashE

Edited to add that we have only had this van a few weeks and our previous one didn't have a remote so if this is a stupid question please be gentle LOL

I would try replacing the battery first, then if that doesn't work, you can move on to reprogramming. If that doesn't work, then you've got something wrong. Could be simple, like the remote is broken or it could be more serious, like a computer problem or the receiver is messed up.