```ruby
module ApplicationHelper

  def admin?
    !current_user.nil? and current_user.admin?
  end

  def event_host?
    event_host = nil
    unless admin?
      else
        event_host = EventHost.where("user_id = ? and event_id = ?", current_user.id, @event.id)
      end
    end
    admin? || !event_host.nil?
  end


  def yes_no (value)
    value ? "Yes" : "No"
  end

  def receipts_exist?
    current_user.user_events.any? {|user_event| user_event.total_price > 0}
  end

  def unpaid_payments?
    current_user.user_events.any? {|user_event| user_event.additional_payments.any? {|payment| payment.unpaid?}}
  end

  def pending_payments
    unpaid_payments = []
    current_user.user_events.each do |user_event|
      user_event.additional_payments.each do |payment|
        if payment.unpaid?
          unpaid_payments << payment
        end
      end
    end
    unpaid_payments
  end

end
```

Correct `event_host?` with nil check on `@event`
user
```ruby
module ApplicationHelper

  def admin?
    !current_user.nil? and current_user.admin?
  end

  def event_host?
    event_host = nil
    unless @event.nil?
      unless admin?
        event_host = EventHost.where("user_id = ? and event_id = ?", current_user.id, @event.id)
      end
    end
    !@event.nil? && (admin? || !event_host.nil?)
  end


  def yes_no (value)
    value ? "Yes" : "No"
  end

  def receipts_exist?
    current_user.user_events.any? {|user_event| user_event.total_price > 0}
  end

  def unpaid_payments?
    current_user.user_events.any? {|user_event| user_event.additional_payments.any? {|payment| payment.unpaid?}}
  end

  def pending_payments
    unpaid_payments = []
    current_user.user_events.each do |user_event|
      user_event.additional_payments.each do |payment|
        if payment.unpaid?
          unpaid_payments << payment
        end
      end
    end
    unpaid_payments
  end
end

```
assistant