Cursors

I'm trying to convert a sql server stored procedure into a postgresql
function and I seem to get stuck on converting the cursor.

sql server snipet
DECLARE @x int, @y int
DECLARE rs CURSOR FOR
SELECT x,y from foo;
OPEN rs
FETECH NEXT FROM rs into @x, @y
WHILE (@@FETCH_STATUS =0)
BEGIN
--do something
FETECH NEXT FROM rs into @x, @y
END
CLOSE rs
DEALLOCATE rs
...

--------------------------
PostgreSQL ???
x int;
y int;
DECLARE rs CURSOR FOR
SELECT x,y from foo;
OPEN rs
FETCH NEXT FROM rs into :x, :y;
While (FOUND) loop
--do something
FETCH NEXT FROM rs into :x, :y;
END LOOP
CLOSE rs;

It complains about an error near FETCH?