multiple variable assignment

Hi - when I run the statement below in a function I get an error basically stating I get 2 column returned by the query

useremailaddress = i.emailaddress,
userusername = ws.username
FROM
public.tblinterimuser AS i INNER JOIN public.tblwebsiteuser AS ws ON
i.websiteuserid = ws.websiteuserid
WHERE
i.websiteuserid = 12;

Question is how do I assign multiple variable values from one statement?

(This will help me get to the bottom of my transaction error which is heading towards user error!!)

Thanks for any and all help