Error : Not allowed to return a result set from a function

[Fernando Rodelo]

Como debe definirse la siguiente funcion para que no se de el error "Not allowed to return a result set from a function"

DELIMITER \\
CREATE FUNCTION bd_devNewvalue(pbase varchar(10))
RETURNS varchar(10)
BEGIN
DECLARE newdocn numeric(10);
DECLARE newdocc varchar(10);

SELECT CAST(pbase AS DECIMAL)+1 INTO newdocn;
SELECT LPAD(newdocn, 10, '0') INTO newdocc;

RETURN(newdocc);
END\\


Supongase que pbase = 5 y se desea obtener 0000000005