i am getting error near insert into rht_users. looking for suggestions on how to get the right query....

create procedure rht_users_insert
(
    IN  p_user_id int,
    IN  p_client_id int,
    IN  p_first_name varchar(50),
    IN  p_last_name varchar(50),
    IN  p_login_id varchar(60),
    IN  p_password varchar(200),
    IN  p_status varchar(10)
);

BEGIN

if not exists(select client_id from rht_users where user_id=p_user_id)then
BEGIN
select p_user_id=ifnull(max(user_id),0)+1 from rht_users


insert into rht_users
(user_id,client_id,first_name,last_name,login_id, password,status)
values(p_user_id,p_client_id,p_first_name,p_last_name,p_login_id,
       p_password,p_status)
END
else
update rht_users set user_id=@user_id,client_id=@client_id,first_name=@first_name,
last_name=@last_name,login_id=@login_id,password=@password,status=@status)
where user_id=@user_id

END