What if I do this..??That circuit is for on/offI found another circuit where they are doing it in this way..Another similar circuit hereThat's for "random fire". OK1 is your zero-cross detector. OK2 is the triac driver, but for your motor (Inductive load!) you need to add a snubber across the power triac and a snubber on the triac driver output, too. See "page 5 of 9" >>>>> http://www.jameco.com/Jameco/Products/ProdDS/277835FSC.pdf
those are ready to use modules..I know about them..But I would like to control it with arduino for other reasons..... You can say a kind of home automation..