style_header("Timeline Display Preferences");
  db_begin_transaction();
  @ <form action="%s(g.zTop)/setup_timeline" method="post"><div>
  login_insert_csrf_secret();
  @ <p><input type="submit"  name="submit" value="Apply Changes" /></p>

  @ <hr />
  multiple_choice_attribute("Comment Format", "timeline-comment-format",
            "tcf", "4", count(azCommentFormats)/2, azCommentFormats);
  @ <p>Each timeline entry contains between one and three of the following subsections:
  @ <blockquote><table border=0 cellpadding=0>
  @ <tr><td>[hash]<td>&nbsp;&nbsp;<td>an artifact hash with a hyperlink to a detail page
  @ <tr><td>comment<td><td>the check-in comment or other text describing the item
  @ <tr><td>(details)<td><td>details about the entry, such as the user, branch, tags, etc.
  @ </table></blockquote>
  @ This setting selects which of the three subsections are included on each
  @ timeline entry and the order in which they are displayed.  When the [hash]
  @ is omitted but the (details) are included, then the hash is shown as one
  @ of the details.  The "comment&nbsp;|&nbsp;(details)" choice means that the
  @ details are displayed in a separate column from the comment.
  @ (Property: "timeline-commit-format")</p>

  @ <hr />
  entry_attribute("Default Timeline Length", 6, "timeline-default-length", "tldl", "50", 0);
  @ <p>The default number of entries in a single /timeline that lacks the "n="
  @ query parameter.
  @ (Property: "timeline-default-length")
  @ </p>

  @ <hr />
  onoff_attribute("Allow block-markup in timeline",
                  "timeline-block-markup", "tbm", 0, 0);
  @ <p>In timeline displays, check-in comments can be displayed with or
  @ without block markup such as paragraphs, tables, etc.
  @ (Property: "timeline-block-markup")</p>