ปิด echo ข้อมูล ก่อนที่เราจะกดปุ่มค้นหาข้อมูลยังไงครับ

  $strSQL = "SELECT data_user.*,data_car.*,data_prb.*,data_ins.* FROM data_user
              left JOIN data_car on data_user.id=data_car.car_id
              left JOIN data_prb on data_user.id=data_prb.prb_id
              left join data_ins on data_user.id=data_ins.ins_id
              WHERE 1 AND data_user.member_id = '$_SESSION[login_true]' 
              ";

  if($_POST["ddlSelect"] != "" and  $_POST["txtKeyword"]  != '')
  {
    $strSQL .= " AND (".$_POST["ddlSelect"]." LIKE '%".$_POST["txtKeyword"]."%' ) ORDER BY data_user.id DESC";
  } 


  $objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
  ?>
  <form name="frmSearch" method="post" action="<?=$_SERVER['SCRIPT_NAME'];?>">
  <table width="100%" border="0" bgcolor="#ffffff">
    <tr>
      <td width="50%" bgcolor="#ffffff" align="center">เลือก
        <select name="ddlSelect" id="ddlSelect">
          <option value="" <?if($_POST["ddlSelect"]==""){echo"selected";}?>>+++++++++++</option>
          <option value="car_num" <?if($_POST["ddlSelect"]=="car_num"){echo"selected";}?>>ทะเบียนรถ</option>
          <option value="name" <?if($_POST["ddlSelect"]=="Name"){echo"selected";}?>>ชื่อ</option>
        </select>
        Keyword
        <input name="txtKeyword" type="text" id="txtKeyword" value="<?=$_POST["txtKeyword"];?>">
      <input type="submit" value="Search">
      </td>
    </tr>
  </table>
</form>
  <table width="100%" border="0">
    <tr>
    <th align="center" width="5%" height="30"><font size="2" color="#FFFFFF">ลำดับ</font></th>
    <th align="center" width="19%"><font size="2" color="#FFFFFF">ชื่อ นามสกุล</font></th>

<?php
  $i = 1;
  while($objResult = mysql_fetch_array($objQuery))
  {
  ?>
    <tr>
     <td align="center" height="25"><font size="2"><?php echo $i;?></font></td>
      <td align="center" height="25"><font size="2"><?php echo $objResult["name"];?>&nbsp;<?php echo $objResult["surname"];?></font></td>