no problem ..
now I using
<div class="tborder" id="threadsearch_menu" style="display:none">
<table cellpadding="4" cellspacing="1" border="0">
<tr>
<td class="catbg">',$txt['setf'],'</td>
</tr>
<tr>
<td class="windowbg" title="">
<form action="', $scripturl, '?action=search2" method="post" accept-charset="', $context['character_set'], '" style="margin: 0;">
<div class="normaltext"><input type="text" name="search" value="" size="25" tabindex="1001"/>
<input type="submit" class="button" value="Go" tabindex="1004" /></div>
<input type="hidden" name="advenced" value="0" size="25" tabindex="1001">
</td>
</tr>
<tr> <td class="catbg"><a href="', $scripturl, '?action=search;advanced" accesskey="4" rel="nofollow">adv. search</a></td>
</tr>
</table>
</form>
</div>';
ı added before </td> .
<input type="hidden" name="board" value="', $board['id'], '" />
<div class="tborder" id="threadsearch_menu" style="display:none">
<table cellpadding="4" cellspacing="1" border="0">
<tr>
<td class="catbg">',$txt['setf'],'</td>
</tr>
<tr>
<td class="windowbg" title="">
<form action="', $scripturl, '?action=search2" method="post" accept-charset="', $context['character_set'], '" style="margin: 0;">
<div class="normaltext"><input type="text" name="search" value="" size="25" tabindex="1001"/>
<input type="submit" class="button" value="Go" tabindex="1004" /></div>
<input type="hidden" name="advenced" value="0" size="25" tabindex="1001">
<input type="hidden" name="board" value="', $board['id'], '" />
</td>
</tr>
<tr> <td class="catbg"><a href="', $scripturl, '?action=search;advanced" accesskey="4" rel="nofollow">adv. search</a></td>
</tr>
</table>
</form>
</div>';
but search all forum again...