Stored Functions in SQL Server?

A function always return a value,and it is called inside the sql statements like normal functions.

Examples:

CREATE FUNCTION CALC_AVERAGE (n1 INT, n2 INT)
  RETURNS INT
   DETERMINISTIC
    BEGIN
     DECLARE avg INT;
     SET avg = (n1+n2*2+n4*4)/8;
     RETURN avg;
    END|