ajax 500 Internal Server Error 질문드려요.

<script type="text/javascript"> function kin() {  var kobj = document.getElementById("wr_1").value;    var subject = "";    var content = "";    $.ajax({        url: "<?=$board_skin_path?>/ajax_re.php",        type: "POST",        data: {            "subject": kobj,            "content": kobj        },        dataType: "json",        async: false,        cache: false,        success: function(data, textStatus) {            subject = data.subject;            content = data.content;        }    }); }</SCRIPT>

<? $subject = $_POST['subject'];$content = $_POST['content'];   $max_wr1 =sql_fetch("select max(wr_1) as m1 from g4_write_corporation_car_log");    $result =sql_query("select * from g4_write_corporation_car_log where (wr_1 between '$subject' and '$max_wr1[m1]') order by wr_1 asc");                      for ($i=0; $wow=mysql_fetch_array($result); $i++) {       $row[$i] = $wow[wr_3];      }$out .= $row[0]."<BR/>";   $out1 .= $row[0]."<BR/>";   die("{\"subject\":\"$out\",\"content\":\"$out1\"}");?>