JumpPad help !! Please help!

How can i make a jump pad and when i mean jump pad i mean like the ones on Unreal Tournament GOTY Morpheus or the ones like in Portal2 but i can animate and make meshes myself im “talkin” or when i mean make i mean scripting what kinda scripting should i use or if its java can some1 help me start it something of the easiest methods in your head that you would be willing to share with me… AND if this doesnt make sense it is fine im really noobish with this editing thing (im an animator lol)