How to make a on click dialog?

Like i want to make a on click function then dialog with choices pops up, if a certain choice is picked another dialogue will be played rinse and repeat until the end of the dialogue, I dont want to use ROBLOX's dialogue because its bad, seriously, theres a word limit and stuff, and I will need to put scripts on the thing anyways... Anybody know how?

(CANT FIND SCRIPTING HELPERS IT DISAPPEARED O.O) http://www.roblox.com/games/296390589/Dragon-Ball-Z-Ultimate-Revelations-Models I need to know how so i dont need to use those roblox dialogues, for instance i want king kai to talk in a dialogue that appears on the bottom, the message also loads letter by letter and the choices appear after.