New Grade
<%= form_for @grade do |f| %>
<%= render 'shared/errors', object: @grade %>
<%= f.label :lecture %>
<%= f.select(:lecture_id, Lecture.all.collect {|p| [ p.name, p.id ] }) %>
<%= f.label :student %>
<%= f.select(:student_id, User.where(role: "student").collect {|p| [ p.login, p.id ] }) %>
<%= f.label :grade %>
<%= f.number_field :grade %>
<%= f.submit 'Create' %>
<% end %>