SQL error when calling stored procedure

CREATE PROCEDURE ILIB_upd_cat_info
 @ilib_category VARCHAR(255),
 @description VARCHAR(255),
 @last_modified DATETIME,
 @modified_by VARCHAR(255),
 @ilib_category_id INT
AS
DECLARE @err INT
BEGIN TRANSACTION
	UPDATE ilib_category 
	SET ilib_category = @ilib_category, 
		[description] = @description, 
		last_modified = @last_modified, 
		modified_by = @modified_by 
	WHERE ilib_category_id = @ilib_category_id
	SELECT @err = @@error
    	IF (@err != 0)
    	BEGIN
      	ROLLBACK TRANSACTION
      	return @err
    	END
COMMIT TRANSACTION
return 0
GO