SQL Help

[nubian]

can someone please help me with this query.
i'm no sql guy and i'm getting syntax error:

i need to add this:
ALTER TABLE `".TABLE_PREFIX."post` ADD COLUMN `warn_flag` int(5) default 0 AFTER attach

my prefix is this:

i tried entering it like this:
ALTER TABLE vb3_post ADD COLUMN `warn_flag` int(5) default 0 AFTER attach

but i'm getting syntax error.
please help.
thanks in advanced.