Larry,
If you are talking about the hydraulic living room slide, it is held in by hydraulic pressure, and if it is not staying closed, you have a leak. There can be 2 different types of leaks. If you have a solenoid valve leaking, it will normally just let the pressure required to hold the slide leak back into the hydraulic reservoir. However, is you are also getting a jack down warning, I would expect an external leak that is resulting in a low fluid level and turning on the jack down warning. Check carefully for an external leak, and low fluid level.
Gerald