Operand should contain 1 column(s) if-clause

I don't understand why these query is wrong. I tried the true and false queries alone and it works, but when i put them in the if-clause it doesn't. Thanks in advance for help :)

SELECT 
IF ( 
(SELECT useronline FROM wp_livechat ORDER BY id DESC LIMIT 1) = 1
, 
(SELECT *
FROM wp_livechat
WHERE id >= (SELECT id 
FROM wp_livechat
WHERE useronline = 0
ORDER BY id DESC
LIMIT 0, 1)
 AND id <= 
(SELECT id 
FROM wp_livechat
WHERE useronline = 1
ORDER BY id DESC
LIMIT 0, 1)
),
(SELECT *
FROM wp_livechat
WHERE id >= (SELECT id 
FROM wp_livechat
WHERE useronline = 0
ORDER BY id DESC
LIMIT 1, 1)
 AND id <= 
(SELECT id 
FROM wp_livechat
WHERE useronline = 0
ORDER BY id DESC
LIMIT 0, 1)
)
);