Redmine/app/views/timelog/_form.html.erb

<%= error_messages_for 'time_entry' %>
<%= back_url_hidden_field_tag %>

<div class="box tabular">
  <% if @time_entry.new_record? %>
    <% if params[:project_id] || @time_entry.issue %>
      <%= f.hidden_field :project_id %>
    <% else %>
      <p><%= f.select :project_id, project_tree_options_for_select(Project.allowed_to(:log_time).all, :selected => @time_entry.project), :required => true %></p>
    <% end %>
  <% end %>
  <p>
    <%= f.text_field :issue_id, :size => 6 %>
    <span id="time_entry_issue"><%= h("#{@time_entry.issue.tracker.name} ##{@time_entry.issue.id}: #{@time_entry.issue.subject}") if @time_entry.issue %></span>
  </p>
  <p><%= f.text_field :spent_on, :size => 10, :required => true %><%= calendar_for('time_entry_spent_on') %></p>
  <p><%= f.text_field :hours, :size => 6, :required => true %></p>
  <p><%= f.text_field :comments, :size => 100 %></p>
  <p><%= f.select :activity_id, activity_collection_for_select_options(@time_entry), :required => true %></p>
  <% @time_entry.custom_field_values.each do |value| %>
    <p><%= custom_field_tag_with_label :time_entry, value %></p>
  <% end %>
  <%= call_hook(:view_timelog_edit_form_bottom, { :time_entry => @time_entry, :form => f }) %>
</div>

<%= javascript_tag do %>
  observeAutocompleteField('time_entry_issue_id', '<%= escape_javascript auto_complete_issues_path(:project_id => @project, :scope => (@project ? nil : 'all'))%>', {
    select: function(event, ui) {
      $('#time_entry_issue').text(ui.item.label);
    }
  });
<% end %>