Thanks for your replay. But I am still confuse, my problem is that I don't understand the "terms" clearly. So, I ask question here and hope my question and the answer are more directly. I am running a zen cart store, all the codes are downloaded from zen cart site. I have not touched the core codes, what I modified is the customer field, such as store name, database connection, css file, add Google Analytics code and so on. If I add WURFL to my zen cart store, do I need to post my store code somewhere?