Simulating download process....

Question

hi guys. asp.net newbie here. how can i simulate the download process thingy wherein (1) i click a button or a link and the download dialog box with Open, Save, Cancel button comes out and asks me if i want to open it from there, or Save it to my local machine (2) i click a button or a link then it downloads the file automatically to my local machine (i tried the WebClient object but i can't seem to make it work). tnx!