[Zope] How to calculate variables using DTML

Hi I just want to create a new variable adding some other vatiables, something like: TTP= ( T_ADT + T_SRC + T_CHD)*TT_NITES As I recieve this variables from a previous form I guess I have to convert them into integer I thought that <dtml-set TTP="(_.int(ADT)+_.int(CHD)+_.int(SRC)*(_.int(TT_NITES))"> would work, but it does not. Hoe can I do this? Thanks !!!!!!!!!!!!!!!!!!!!!!!!! _________________________________________________________________ Charla con tus amigos en línea mediante MSN Messenger: http://messenger.yupimsn.com/