update statement in MySQL SP showing missing end error - mysql

Question

I have a stored procedure like the following. There is an error showing at the update statement before the cursor declaration. When I remove the cursor statement, the stored procedure works fine. Why can't be there an update statement before the cursor statement?
DROP PROCEDURE IF EXISTS GenerateAlert;
DELIMITER $$
CREATE PROCEDURE GenerateAlert()
BEGIN
DECLARE done INTEGER DEFAULT FALSE;
DECLARE temp_project_id INT DEFAULT 0;
DECLARE temp_finish_time DATETIME DEFAULT NOW();
DECLARE _message_class INT DEFAULT 3;
DECLARE proj_user_id INT DEFAULT 0;
-- get message text template
DECLARE message_template VARCHAR(255) DEFAULT
(
SELECT alert_message_template FROM alerts WHERE id = 6
);
-- get maximum allowed minutes
DECLARE allowed_time INT DEFAULT
(
SELECT alert_value_1 FROM alerts WHERE id = 4
);
-- flag all messages with class 3 to deleted = true
UPDATE messages
SET is_deleted = 1
WHERE messages_class = 3;
DECLARE _cur CURSOR FOR
SELECT d.project_id, MAX(finish_time)
FROM
client_docs AS d INNER JOIN
issues AS i ON d.project_id = i.project_id INNER JOIN
working_times AS t ON i.id = t.issue_id
WHERE
d.status = 1 AND
t.finish_time IS NOT NULL AND
t.category = 1
GROUP BY d.project_id;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
OPEN _cur;
read_loop: LOOP
FETCH _cur INTO temp_project_id, temp_finish_time;
IF done THEN
LEAVE read_loop;
END IF;
-- add more minutes to finish time
SET temp_finish_time = DATE_ADD(temp_finish_time, INTERVAL allowed_time MINUTE);
IF temp_finish_time < NOW() THEN
-- this project must be alerted
-- get project user
SELECT c.staff INTO proj_user_id
FROM
projects AS p INNER JOIN
clients AS c ON p.client_id = c.id
WHERE
p.id = temp_project_id;
END IF;
END LOOP read_loop;
CLOSE _cur;
END
$$
DELIMITER ;

Answer 1

Found the answer: The declaration statments must come before any other transactional statement in MySQL stored procedure.
SQL, missing end, but why? Second comment in the answer.