app/views/meetups/_review_form.html.erb
<%= form_for([@meetup, review.session, review],:html=>{:remote=>true}) do |f |%>
<div class="row">
<div class="field col-2">
<%= f.label :mark %><br />
<%= f.select :mark, [5,4,3,2,1], {}, class: 'form-control' %>
</div><br/>
<%= f.hidden_field :meetup_id, value: @meetup.id %>
<%= f.hidden_field :user_id, value: current_user.id if current_user %>
<div class="field col-10">
<%= f.label :review %><br />
<%= f.text_field :review, autofocus: true, class: 'form-control' %>
</div><br/>
</div><br/>
<%= f.submit class: 'btn btn-primary right' %>
<% end %>