มัน error แบบนี้ ต้องแก้ยังไงครับ select max(columnname) from tb where date_at(columname3,'%Y%m')='200901' group by date_at(columname2,'%d')

<?
//select max(columnname) from tb where date_format(columname3,'%Y%m')='200901' group by date_format(columname2,'%d')
$strSQL = 
"SELECT
`tb_province`.`name_prov`,
`tb_temperature`.`areas`,
`tb_areas`.`name_areas`,
MAX(temp_hight),
`tb_temperature`.`date_temp`
FROM
`tb_areas`
Inner Join `tb_province` ON `tb_province`.`id_prov` = `tb_areas`.`prov`
Inner Join `tb_temperature` ON `tb_areas`.`id_areas` = `tb_temperature`.`areas`
WHERE
MONTH(tb_temperature.date_temp)='$mm' AND YEAR(tb_temperature.date_temp)='$yy'

GROUP BY tb_temperature.date_temp

ORDER BY
`tb_temperature`.`date_temp` ASC";


$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");

$name = array();
$temp = array();

$numrw=mysql_num_rows($objQuery);
if ($numrw == 0){
echo "ไม่พบข้อมูล";
}else{	
?>
	<table width="100%" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td colspan="2" align="center" valign="middle">
		<img src='graph_lp_mount.php?<?echo $_SERVER['QUERY_STRING'];?>'>
		</td>
        </tr>
      <tr>
        <td width="50%" align="right" valign="middle">&nbsp;</td>
        <td width="50%" align="left" valign="top">&nbsp;</td>
      </tr>
      <tr>
        <td colspan="2" align="center" valign="top">
		
		<table width="450" border="1" align="center" cellpadding="0" cellspacing="0" bordercolor="#993300">
          <tr>
            <td class="head" width="40%" height="30" align="center" valign="middle" bgcolor="#CC6600">วันที่</td>
              <td class="head" width="30%" height="30" align="center" valign="middle" bgcolor="#CC6600">พื้นที่</td>
              <td class="head" width="30%" height="30" align="center" valign="middle" bgcolor="#CC6600">อุณหภูมิ (<sup></sup> ํC)</td>
            </tr>
<?
$ii=0;
while($objResult = mysql_fetch_array($objQuery))
{

$d_temp= $objResult["date_temp"];
$tem_h= $objResult["MAX(temp_hight)"];

echo $tem_h;
$x1 = mysql_query("SELECT name_areas,temp_hight FROM tb_areas
Inner Join `tb_temperature` ON `tb_areas`.`id_areas` = `tb_temperature`.`areas`
WHERE temp_hight='$tem_h' && date_temp='$d_temp'");


//$area= $objResult["name_areas"];
echo $area= mysql_result($x1,0);


$prov= $objResult["name_prov"];

$name[] = $area;
$temp[] = $tem_h;
$date = sprintf('%04d-%02d-%02d',$y,$m,$d);
?>
          <tr>
            <td width="40%" height="30" align="center" valign="middle"><?echo thaidate($d_temp);?></td>
            <td width="30%" height="30" align="left" valign="middle"><?echo '&nbsp;&nbsp;'.$area;?></td>
            <td width="30%" height="30" align="left" valign="middle"><?echo '&nbsp;&nbsp;'.number_format($tem_h, 1);?></td>
            </tr>
          <?}}?>