Ask help for sql server

update tbl_surveys
set site_specific_3=(select site_specific_3 from youthmapentry.dbo.tbl_surveys
where site_number=youthmapentry.dbo.tbl_surveys.site_number
and [id]=youthmapentry.dbo.tbl_surveys.[id])

then I got this error
Server: Msg 279, Level 16, State 3, Line 1
The text, ntext, and image data types are invalid in this subquery or aggregate expression.

How can I do this update,

Thanks a lot