if someone else gets the patent before you do then you will be in trouble won't you? I think a the laws allows it however it specifically mentions that "Provisional applications for patent cannot claim the benefit of a previously-filed application, either foreign or domestic."... so its safer to keep your inventions with you before you patent it, its just common sense. If you want to show it to someone then sign a non-disclosure agreement. If you share the details with me, i will be in a better position to guide you. thanks.