I have been reading through this appnote http://ww1.microchip.com/downloads/e...tes/40171a.pdf and noticed the presence of two extra capsacitors namely C1 and C2 in the appnote schematic ..what is the function of these in this instance?

I have updated my design (see attached file) to include a zero-crossing sensor and have connected the TRIAC.
My concern is the value of the TRIAC resistor and that's the reason for the ???.
If there are any suggestions/concerns or changes to be made please let me know.

Kind regards

Dennis