Got a door which does not have the spring lock which locks the door when you close it. Leave the door closed, and it'll soon be wide open even with a little gust of wind.
Currently we're wedging a handful of paper between the door and the door frame, so that it'd stay closed when we close it. The more elegant option of course, is to use a damper which will slowly close the door once it's been opened.
But dampers are a bit expensive for such a trivial function, and then there are the installation charges too. Is there a better way to ensure the door remains closed (a simple, elegant, less expensive option. Installing a spring lock is expensive)?
EDIT: One more requirement from my Dad was that since with any of the below solutions the door will appear to be closed, the people inside the house would think it is locked, while any stranger who comes along and slightly pushes the door will be able to get in. It'd help if the door closing mechanism has a way to let the people indoors know that the door is just closed, and not locked. Safety. Problem is that an LED would require a small transformer for getting power from the AC mains (batteries aren't really a long-term option). Having a safety mechanism is a bit tricky.