def my_account_json
      return if !logged_in?    
      invoice = Invoice.find(params[:invoice_id])      
      if invoice.customer_id != logged_in_user.id        
        render :json => { :error => "The given invoice does not belong to you." } 
        return
      end
      render :json => invoice.shipping_address      
    end
def my_account_json
      return if !logged_in?    
      invoice = Invoice.find(params[:invoice_id])      
      if invoice.customer_id != logged_in_user.id        
        render :json => { :error => "The given invoice does not belong to you." } 
        return
      end
      render :json => invoice.shipping_address      
    end
===========================================================================
 @route GET /my-account/invoices/:invoice_id/shipping-address/json