gecko-dev/editor/dialogs/imageformatdlog.xml

<?xml version="1.0"?>
<?xml-stylesheet href="EditorDialog.css" type="text/css"?>
<!DOCTYPE window SYSTEM "imageformatdlog.dtd">
<window xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
        xmlns:html="http://www.w3.org/TR/REC-html40">

  <table xmlns="http://www.w3.org/TR/REC-html40" cellspacing="10">
    <tr>
      <td>

        <p>File Name:</p>
        <input type="text" size="40" length="40" maxlength="40" />
        <p/>
        <br/>
        <p>Pick a Format:</p>
        <select width="100%" size="8" name="fileFormatList">
          <optgroup label="format">
            <option label="format1" value="format 1">Format 1</option>
            <option label="format2" value="format 2">Format 2</option>
            <option label="format3" value="format 3">Format 3</option>
            <option label="format4" value="format 4">Format 4</option>
            <option label="format5" value="format 5">Format 5</option>
            <option label="format6" value="format 6">Format 6</option>
          </optgroup>
        </select>

        <p/>
        <input type="button" id="helpbutton" value=" Help " disabled />
        <input type="button" id="cancelbutton" value=" Cancel " />
        <input type="button" id="okbutton" value=" OK " disabled />
      </td>
    </tr>
  </table>

</window>