T-SQL (SS2K8) :: How To Retrieve Columns Name As Single Row From Table In Dynamic Way

I need to retrieve columns names(instead of select * from) as single row from table in dynamic way.

i m using following query.

its working fine while using from selected database. but its not working when i m running from different database.

DECLARE @columnnames varchar(max)
select @columnnames = COALESCE(@columnnames,'')+column_name+',' from INFORMATION_SCHEMA.COLUMNS(nolock)
where table_name='table_20141224'
select @columnnames

I need to pass database name dynamically like using by variable.

Is this possible to use variable after from clause. or any other methods?

eg:

DECLARE @columnnames varchar(max)
DECLARE @variable='db_month11_2014'
select @columnnames = COALESCE(@columnnames,'')+column_name+',' from @VARIABLE.INFORMATION_SCHEMA.COLUMNS(nolock)
where table_name='table_20141224'
select @columnnames