Do this test - while you press the trunk button, listen for a clicking sound coming from the glovebox. If there is a clicking sound, then the problem is with your trunk release electric motor being jammed, which is a common problem with Contours. If there is no clicking sound, then the problem is either with a faulty trunk button in your keyfob as Nic suggests, or with the actuator behind the dash. Do a search in Troubleshooting for more info. There are a lot of discussions on key fobs and trunk release motors and such...
