Hi guys, i am new to rails,i really want to know how to use checkbox on form_with type

<div class="field">
  <%= form.label :course_type %>
  <%= form.check_box :ctype, {:id => "post_ctype"} %>checkbox 1 
  <%= form.check_box :ctype, {:id => "post_ctype"} %>checkbox 2
</div>

check box is not working properly,so i need a proper syntax for check box in rails,I hope u all