arduino and Max/MSP

the serial object did read the board! and the code you sent and the patch work! but what I'm tring to do is getting info from the board not the other way around!
I need to read on/off msgs from the board! i have switchs so what i want is for each time the switch is on to read a bang on my Max patch! how can i do that? and should i be writing code to upload to the board too using the arduino IDE? am still new to all this so... :-?