Why doesn't thisw work - syntax error

[Martina Long]

I'm used to writing stored procedures in MS SQL and this is what I would write to return all of the fields in a table clientdetails where the clientnumber being sent in is in the database.

CREATE PROCEDURE `leswana`.`accounts` (IN @clientnumber INT)
BEGIN

select * from clientdetails where clientnumber=@clientnumber

END

What is wrong with this for MySQL, how do I write it?