如何在目标c中使用某些Web服务时在url中传递函数名？

I am a beginner in i phone development.I am,right now, using web service to fetch data on my page.now the thing is that i have 2 functions in the same webpage. now i want to fetch data from only 1 function at the time when my url is passed. so how can i pass the argument? note that,my main purpose is to convert data into json format.my URL that i run in web browser is like :I am a beginner in i phone development.I am,rig