ช่วยดูให้ทีครับ ว่าผมทำผิดตรงไหน เรื่องการ อัพเดทข้อมูลครับ

<? 
header("Content-Type:Text/html; charset=tis-620");
include("connect.php");
$search=iconv("utf-8","tis-620",$_POST['tSearch']);
$mode=$_POST['tMode'];
$mql="select * from member";
if($mode="SEARCH"){
$mql.=" where muser like'%$search%' or mname like'%$search%' or mnic like'%$search%' ";
}
$mql.="order by mdate desc";
$mqr=mysql_db_query($db,$mql);
$num=mysql_num_rows($mqr);
echo '<div align=left>',"Keyword : ",'<b>',$search," &nbsp;มี ".$num.'รายการ </b>','</div>','<br>';
?>
<style type="text/css">
.redtxt{ font-weight:bold; font-size:10pt; color:#FF0000; background-color:#FFFF00; height:25; }
</style>
<form name="form1" method="post" action="blog.member.php">
  <table width="100%" border="0" cellspacing="1" cellpadding="3">
    <tr>
      <td width="17%"><strong>Username</strong></td>
      <td width="17%"><strong>ชื่อเล่น</strong></td>
      <td width="46%"><strong>ชื่อ - สกุล </strong></td>
      <td width="5%"><strong>เพศ</strong></td>
      <td width="9%" align="center"><strong>ระงับ</strong></td>
      <td width="6%" align="center"><strong>ลบ</strong></td>
    </tr>
    <?    $num=mysql_num_rows($mqr);
	if($num!=0){ 
	$i==0;
			  while($mrs=mysql_fetch_array($mqr)){
			  $i++;
			  
			  $sex=$mrs['msex'];
			  if($sex=='1'){
  $color="#C2FCCA";
  } 
  if($sex=='2'){
  $color="#FCE2FB";
  } 
			   
		
	$a=$mrs['muser']; 
	$b=$mrs['mnic'];
	$c=$mrs['mname']; 
	  	   
			   if($search<>""){
$re='<span class="redtxt"><b>'.$search.'</b></span>';
$resulta=str_replace($search,$re,$a);
$resultb=str_replace($search,$re,$b);
$resultc=str_replace($search,$re,$c);
} else { 
$resulta=$mrs['muser']; 
$resultb=$mrs['mnic']; 
$resultc=$mrs['mname']; 
}
			  ?>
    <tr>
      <td bgcolor="<?= $color; ?>"><?= $resulta; ?></td>
      <td bgcolor="<?= $color; ?>"><?= $resulta; ?></td>
      <td bgcolor="<?= $color; ?>"><?= $resulta; ?></td>
      <td bgcolor="<?= $color; ?>"><img src="../images/<?= $mrs['msex']; ?>.gif"></td>
      <td align="center" bgcolor="<?= $color; ?>"><input name="block<?= $i; ?>" type="checkbox" id="block<?= $i; ?>" value="<?= $mrs['muser']; ?>" <? if($mrs['block']==1){ ?>checked="checked"<? } ?>></td>
      <td align="center" bgcolor="<?= $color; ?>"><a href="del.member.php?dm=<?= $mrs[0]; ?>" onClick="return confirm('แน่ใจว่าต้องการลบ สมาชิกรายนี้ออกจากระบบ')"><img src="../images/Bin.gif" alt="เจ้าของ ลบเมล์" width="20" height="20" border="0"></a></td>
    </tr>
    <? }}else { ?>
    <tr>
      <td colspan="6" align="center"><img src="../images/signup-error.gif" alt="Ohogig ไม่พบข้อมูล" width="16" height="16" align="absmiddle"><b style="color:#d00;">ไม่มีรายชื่อที่ต้องการ -</b> </td>
    </tr><? } ?>
    <tr>
      <td>&nbsp;</td>
      <td>&nbsp;</td>
      <td><input name="i" type="hidden" id="i" value="<?= $i; ?>" /></td>
      <td>&nbsp;</td>
      <td><input type="submit" name="Submit" value=" Update " /></td>
      <td>&nbsp;</td>
    </tr>
  </table>
</form>

<? 
session_start();
ob_start();
include("connect.php");
$m=$_POST['i'];

$x=0;
for($i=0; $i<$m; $i++){
$x++;
$block=trim($_POST["block$x"]);

echo "x : $x  m : ".$i.' block : '.$block.'<br>';
		if($block!="")
		{
			$sql="update member set block=1";
			$sql.=" where muser='$block'";
			
			$rs=mysql_db_query($db,$sql);
		}
		else {
			$sql="update member set block=0";
			$sql.=" where muser!='$block'";
			$rs=mysql_db_query($db,$sql);
			}
			}


header("Location:member.php");
?>