Prepared statments error

DELIMITER $$

 DROP PROCEDURE IF EXISTS epic_from_exch_epic$$

 CREATE PROCEDURE epic_from_exch_epic()

 BEGIN

 DECLARE x  INT;

 DECLARE y  INT;

 DECLARE str  VARCHAR(255);

  SET x = 1;

  SET y = 20000000;

 WHILE x  <= y DO

 SET  str = CONCAT(str,x,',');

 SET @idlow = 26423400;

SET @idhi = @idlow + 2000000;

UPDATE sharescope_ex_ep 

SET epic = substring_index(exch_epic, ':' , -1)

WHERE 

epic = ''

AND id_sharescope_data between @idlow and @idhi;

 SET  x = x + 1; 

 END WHILE;

 select * from sharescope_ex_ep 

WHERE id_sharescope_data > (y - 10)

order by id_sharescope_data

limit 100;

select * from sharescope_ex_ep order by id_sharescope_data DESC limit 10;

 END$$

DELIMITER ;