c# with sql server

i need help...... i`m programming with c# and using sql server 2000 i have a database that i have created on sql server and i want to know if it`s possible to know the name of the relations between the tables. i want to emphasis very important thing, i have already defined the relations in the database between the tables (primary key and foreign key) and i just want to know how can i use this relation? what kind of functions in c# programming, retrieve this name of relations or what kind of function can help me to get data from tables using this relations? this help very critical for me...... Thanking you in anticipation koby