Accessing the menu items depending on user login

Question

Hi,
    i have created a master page with some of the menu items and i have created subpages also.
 now i wanted to give write the code for accessing menu items depending upon user login. ex: for the user admin i have to show all the menus and for manager i have restrict some menus. I am not having idea please suggest me regarding this using asp.net


With Regards
Ashwini