php通过odbc读取informix数据出现乱码，应该怎么修改？

<code>今天日期:12-12-04险种      单数      保费����        994     1974911.90������      20      68230.00������      10      3750.00������      52      8026.43�Ҳ���      24      15090.00�ϼ�        1100        2070008.33</code>

<code>            <title>PHP and ODBC 1</title>        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">        <meta http-equiv="Content-Type" content="text/html; charset=gb2312">        <?php $conn=odbc_connect('sky123','picctj','picctj');        if (($conn)) {           echo "今天日期:";echo date("y-m-d");          echo odbc_errormsg ($conn );          echo "</p>\n";        }        $sql = "SELECT * from tongji";        $rs = odbc_exec($conn,$sql);        echo "<table>";        echo "<tr>
<td>险种</td>
<td>单数</td>
<td>保费</td>
</tr>";        while (odbc_fetch_row($rs))         {         $result1 = odbc_result($rs,"xianzhong");          $result2 = odbc_result($rs,"danshu");         $result3 = odbc_result($rs,"baofei");       iconv("Latin-1","gb2312",$result1);//测试的代码        echo "<tr>";             echo "<td>$result1</td>";         echo "<td>$result2</td>";         echo "<td>$result3</td>";         echo "</tr>";        }        odbc_close($conn);        echo "</table>";    ?>    </code>