adjusting parameters

Hello,I want to change some parameters in the algorithm,for example,the number of recommendations to see the recommendation results,so I changed the file tstsuggest.c in C-FREE(an IDE for c programming)?and imported the suggest.h into the "include" file folder of C-FREE?then I tried to run the corrected program but failed. I guess it was because the suggest.lib was not used correctly,so I create a new project and imported the tstsuggest.c into this project and also set this project connecting to the suggest.lib,but it still failed.
Briefly, how can I change the program and can still run it correctly?