php mysql สอบถามเรื่องปัญหาฐานข้อมูลมีปัญหากับภาษาไทยในการใช้ database ครับ

<?
# »ÃѺ»Ãا « 2550-05-20 (Version 1.0)
include("header.php");
include("config.php");
$connect = mysql_connect("$mysql_host","$mysql_user","$mysql_password");
if (isset($_GET["id"]) && strlen($_GET["id"]) > 0){
  $sql = "SELECT regist.*,mainsubject.subjectid,mainsubject.classroom,mainsubject.no FROM 
  mainsubject LEFT JOIN regist ON mainsubject.subjectid = regist.subjectid	 
  WHERE regist.studentid='".$_GET["id"]."' Or regist.studentid Is Null";
  $result = mysql_db_query($mysql_db,$sql);
  if ($result) echo "<table width=760 align=center bgcolor=#dddddd>"; else exit; 
  $i =0;
  $oclass = "";
  while ($object = mysql_fetch_object($result)) {
    if ($i == 0) {
	  echo "<tr bgcolor=#dddddd><td colspan=4>
 	  <b>ÃÒ§ҹáÊ´§¼ÅÃÇÁ¤Ðá¹¹ àÅ×Í¡µÒÁÃËÑʹѡàÃÕ¹ ᡵÒÁÃдѺªÑé¹</b><br> 
	  $object->studentid ";
      $sql = "select * from student where studentid ='".$_GET["id"]."'";      
      $rstudent = mysql_db_query($mysql_db,$sql);
      if ($ostudent = mysql_fetch_object($rstudent)) echo "$ostudent->sfname $ostudent->slname ";
    }
	if ($oclass != $object->classroom) {
      if ($i != 0) {
		echo "<tr bgcolor=#dddddd><td colspan=4 align=right>ÃÇÁ¤Ðá¹¹: $tscore ¨Ó¹Ç¹ÇÔªÒ: $tsubject ¤Ðá¹¹à©ÅÕèÂ:" . substr($tscore / $tsubject,0,5);	
        $tscore = 0;
        $tsubject = 0;
	  }
      echo "<tr bgcolor=#ddffdd><td colspan=4>$object->classroom";	
	}
    $tscore += $object->score;
    if (strlen($object->score) > 0) $tsubject += 1;
    $oclass = $object->classroom;
	echo "<tr bgcolor=";
    if ($i++ % 2 == 0) echo "#ffffdd>"; else echo "white>";
    // echo "<td>$i";
    // foreach($object as $o) echo "$o"; echo "<br>";
	echo "<td>$object->no <td>$object->subjectid";
    $sql = "select * from subject where subjectid ='".$object->subjectid."'";      
    $rsubject = mysql_db_query($mysql_db,$sql);
    if ($osubject = mysql_fetch_object($rsubject)) echo " $osubject->subjectname";
	echo "<td>$object->score";
	echo "<td>$object->grade";
  }
  echo "<tr bgcolor=#dddddd><td colspan=4 align=right>ÃÇÁ¤Ðá¹¹: $tscore ¨Ó¹Ç¹ÇÔªÒ: $tsubject ¤Ðá¹¹à©ÅÕèÂ:" . substr($tscore / $tsubject,0,5);	  
  echo "</table>Total records : ".mysql_num_rows($result);
}
include("footer.php"); 
?>