이게 무슨 에러인가요?

Fatal error: Call to undefined function exp_bar() in C:\APM_Setup\htdocs\st\skin\outlogin\1\outlogin.skin.2.php on line 37

아래는 원 코드입니다.

<?
if (!defined("_GNUBOARD_")) exit; // 개별 페이지 접근 불가

$home_name = get_text($config[cf_home_name]);
?>

<style>
.login_input { font-family:dotum; font-size:8pt; color:#777777; border-top:1px solid #d9d9d9; border-bottom:1px solid #d9d9d9; border-left:1px solid #d9d9d9; border-right:1px solid #d9d9d9; letter-spacing:0px; padding-top:3px; padding-left:5; padding-right:0; padding-bottom:0; width:116px; height:18px; }
.login_text { font-family:dotum; font-size:8pt; padding-top:8px; padding-bottom:3px; color:#666666; letter-spacing:-0.5px; }
.login_text1 { font-family:dotum; font-size:8pt; color:#777777; padding-top:5px; color:#999999; padding-right:10px; }
</style>

<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr height="100">
<td width="3" background="<?=$outlogin_skin_path?>/img/bg_left.gif"></td>
<td background="<?=$outlogin_skin_path?>/img/bg.gif" valign="top">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr height="30">
<td width=8></td>
<td class="login_text">
<? if ($is_admin == "super" || $is_auth) { ?><a href="<?=$g4['admin_path']?>/"><b><?=$nick?></b></a><? }else{ ?><b><?=$nick?></b><? } ?> (권한 : <?=$member[mb_level]?>)
</td>
<td class="login_text" align="right"><a href="<?=$g4['path']?>/service/mypage/index.php">마이페이지</a>&nbsp;</td>
<td></td>
</tr>
</table>
</td>
</tr>
<tr>
<td>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="8" rowspan="3"></td>
<td><?=exp_bar($member[mb_id],$member[mb_point],1);?></td>
<td rowspan="2" width="64"><? $profile_image = "$g4[path]/data/profile_image/{$member[mb_id]}";
if (!$member[mb_id]||!file_exists($profile_image)) echo "<img src='".$outlogin_skin_path."/img/noimage.gif'>"; else echo "<img src='$profile_image' width='60' height='60'>";
?></td>
</tr>
<tr>
<td>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td class="login_text"></td>
<td class="login_text"><a href="javascript:win_memo();">쪽지</a> : <span style="color:#aa3f33"><?=$memo_not_read?></span></a>&nbsp;<span style="color:#cccccc;">|</span>&nbsp;<span style="color:#aa3f33"><a href="javascript:win_point();"><?=$point?></a></span> 점</td>
</tr>
<tr height="2"><td colspan="2" background="<?=$outlogin_skin_path?>/img/_bar.gif"></td></tr>
<tr>
<td class="login_text" colspan="2"><a href="javascript:win_scrap();">스크랩</a>&nbsp;<span style="color:#cccccc;">|</span>&nbsp;<a href="<?=$g4['bbs_path']?>/logout.php" style="color:#a7000c;">로그아웃</a></td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
<td width="3" background="<?=$outlogin_skin_path?>/img/bg_right.gif"></td>
</tr>
</table>