*without submit*
<form name="archiveform" action="">
<select name="archive_chrono" onchange="window.location = (document.forms.archiveform.archive_chrono[document.forms.archiveform.archive_chrono.selectedIndex].value);">
<option value=''>按月彙整</option>
<?php wp_get_archives('format=option&show_post_count=1'); ?>
</select>
</form>
*without submit*
<li id="archives">按月彙整<!-- <?php _e('Archives'); ?> -->
<ul>
<form action="" name="Month" id="Month">
<select name="menu_month" id="menu_month" onchange="jumpMenu('parent',this,0)">
<option value="">請選擇</option>
<?php wp_get_archives('format=option&show_post_count=1'); ?>
</select>
</form>
</ul>
</li>