we cannot perform Dml inside functions

CREATE FUNCTION UDF_DMLOperationTest()
RETURNS INT
AS
BEGIN
INSERT INTO LocationTable VALUES(167,'XXX') -- we are trying to do DML operation inside a function 
RETURN 1
END

Above CREATE FUNCTION code gives this error:
Invalid use of a side-effecting operator 'INSERT' within a function.

NOTE: This is one of rule we all should know.....

One more important thing is we can apply DML operation on table variable inside a function