stopping scrollrect if it is about to leave the desired space

too sum it up, i have two panels i.e. p1 is the parent of p2 where p1 masks p2, p2(containing some buttons) has a scrollrect on it and i want that p2 should stay in the bounds of p1. When i scroll with elasticity, p2 is able to leave the visible bounds.i want p2 to stay in the bounds of p1 i.e. if p2 reaches any of the ends it should bounce/snap back into the visible bounds. i tried horizontalNormalisedPosition but could not understand how it works. EVERYTHING IS IN HORIZONTAL FLOW. thank you