search for: row_invoices

I have a problem with the association. I have the model called Invoice whit the associations: belongs_to :company belongs_to :client belongs_to :type_invoice has_many :row_invoices belongs_to :bank belongs_to :payment When i create the invoice i use a session variable, so i can add all the information i wont and I can save all at the end. This is all ok. def new session[:invoice] = Invoice.new # new invoice session[:invoice].company = Company.find(1) # load company ......