if else to render a different form in the view of a rails 2 app

Question

I am trying to render one of two slightly different forms with an unless else:

unless many_items
     form_tag purchases_url(:item1 => item1), :id => "id1_#{item1}", :method => "post", :class=> "order-form" do 
 else 
      form_tag purchases_url(:item1 => item1, :item2 => item2), :id => "upgrade_#{item2}", :class => "upgrade_form" do
end

rest of form
    button

<%end%>

but I get an error, of course. I don't really know haw to do this..

Answer 1

I used a nil to prevent from the second variable to exist

parent_order = item2.present? ? item2 : nil
form_id = gig.is_item? ?  "1#{gig.id}" : "2#{gig.id}"
form_class = gig.is_item? ? "1" : "2"

 form_tag purchases_url(:item1 => item1 ,:item2 => items), :id => form_id, :method => "post", :class=> form_class do 

 %>