I have recently purchased a full-size round trampoline for my two kids, 5 and 7. It is in our fenced (3 1/2 ft.) backyard, which is visible to at least a dozen homes in the neighborhood. All of a sudden, every kid in the neighborhood wants to come over and make friends---and the first thing they want to do is jump. These are kids of all ages from families I do not know. Is there a waiver of liability that I should have signed? If so, where can I find such a document? I live in N.C. Thanks so much. Lisa