Change the fill color of an object in illustrator using extendscript

Hi

I have a script that scan through items on the page in an illustrator file. I would like to be able to say if a particular colour is found, say c=0, m=0,y=100,k=0 (yellow) change that colour to cyan. I'd like to use an if statement so

  if (currentItem.fillColor= c=0, m=0,y=100,k=0) {

code to change it to c=100, m=0,y=0,k=0 in here

}

Really struggling with this and thought it would be obvious.

Alternativly is it possible to specify a colour and change all the items on a page that are that colout to a different colour. I the same way that you would use the select same fill colour from the Select menu

Many thanks in advance

Bob