Hello!!!

I have a problem to see if a field in a table is empty or not but I have to respect the querie:

PHP Code:
$sql = "select * from agenda_geral where agenda='desporto' and Bmonth = month(now()) + ".$modifier." and area_ID = 1 order by Bday" ; 
How can I see if the field Bmonth have the next month of the current.

Can You help me??