Try to assess if the caravan door is definitely bent by placing a straight edge against it, if it is the from inside the caravan gently pull the door shut until you can see where it is bent to, by placing a piece of timber between the door and the jam you can exert force on the door very slowly and straighten it, make sure that you keep rechecking the door or you may end up with it bending too far
Paul (Bristol), November 2008