<%= form_for @course, :url => {:action => "update_course"}, html: {class: "form-horizontal main-forms"} do |f| %>

<%= f.label :course_name, :class => "control-label muted" %>

<%= f.text_field :course_name %>

<%= f.submit "Save", :class => "btn btn-primary" %> Cancel

<% end %>