using ILIKE xyz where xyz is a function parameter

Hi,

I'm stuck here.

I have a function that I would like to pass a text string and have the
function perform ILIKE on that passed string.

create or replace function foo( sLastName text )
AS

Select * from Person where LastName ILIKE sLastName;
....


What is the syntax for using ILIKE '%sLastName%' ??

Thanks for any tips,

Frank