How to format a join table form to display multiple checkboxes for values from one of the linked tables in Symfony?

Question

Apologies if this is something really simple that I've missed.

I have 3 tables and related forms in symfony 1.4 (using Doctrine) for a website for local tradesmen:

Profile
  columns:
    name: { type: string(255), notnull: true}
    email: { type: string(255), notnull: true, unique: true }
    phonenumber: { type: string(255), notnull: true, unique: true }

Trade
  columns
    description: { type: string(255), notnull: true}

ProfileTrade
  columns
    profile_id: { type: integer }
    trade_id: { type: integer }
    certified: { type: boolean, default: 0 }
    certificationdescription: { type: string(255) }
  relations
    Profile: {onDelete: CASCADE, local: profile_id, foreignAlias: ProfileTradeProfile }
    Trade: {onDelete: CASCADE, local: trade_id, foreignType:many, foreignAlias: ProfileTradeTrade }

Embedding the ProfileTrade form in the Profile form is not a problem, however I'd like to change the format of the form so that it displays in a table, where the leftmost column contains the name of each trade, with 2 checkboxes and a text field for CertificationDescription displayed for each row. 1 checkbox would control whether an entry in created for that trade in ProfileTrade, and one would control the certified value. What's the best way of doing this?

Thanks.