ถ้ากดค้นหาข้อมูลแล้วไม่เจอข้อมูล ให้มันแสดงผลว่า "ไม่พบข้อมูล " ต้องแก้ส่วนไหนครับ

<form name="frmSearch" method="get" onSubmit="JavaScript:return fncSubmit()"; action="del.php">
  <table width="599" border="0" align="center">
    <tr>
      <th>ห้อง
        <label>
          <select name="txtKeyword" id="txtKeyword" value="<?=$_POST["txtKeyword"];?>">
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="6">6</option>
       
          </select>
        </label>
      <input type="submit" value="&#3588;&#3657;&#3609;&#3627;&#3634;"></th>
    </tr>
  </table>
</form>

<?php
if($_GET["txtKeyword"] != "")
	{
	include("../connect.php");
	// Search 
	$strSQL = "SELECT * FROM student WHERE (class='".$_GET["txtKeyword"]."')";
	$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
	$numobj=mysql_num_rows($objQuery );
	if($numobj > 0){
	?>
	<script language="JavaScript">
	function ClickCheckAll(vol)
	{
	
		var i=1;
		for(i=1;i<=document.frmMain.hdnCount.value;i++)
		{
			if(vol.checked == true)
			{
				eval("document.frmMain.chkDel"+i+".checked=true");
			}
			else
			{
				eval("document.frmMain.chkDel"+i+".checked=false");
			}
		}
	}

	function onDelete()
	{
		if(confirm('Do you want to delete ?')==true)
		{
			return true;
		}
		else
		{
			return false;
		}
	}
</script>
<form name="frmMain" action="delall.php" method="post" OnSubmit="return onDelete();">
<?php
include("../connect.php");
$strSQL = "SELECT * FROM  student";
$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
?>
<table width="726" border="1">
  <tr>
    <th width="91"> <div align="center">CustomerID </div></th>
    <th width="98"> <div align="center">card </div></th>
    <th width="198"> <div align="center">name </div></th>
    <th width="97"> <div align="center">username </div></th>
    <th width="59"> <div align="center">password </div></th>
    <th width="71"> <div align="center">pic </div></th>
    <th width="30">room</th>
    <th width="30"> <div align="center">
      <input name="CheckAll" type="checkbox" id="CheckAll" value="Y" onClick="ClickCheckAll(this);">
    </div></th>
  </tr>
  
<?php
$i = 0;
while($objResult = mysql_fetch_array($objQuery))
{
$i++;
?>
  <tr>
    <td><div align="center"><?php echo $objResult["id"];?></div></td>
    <td><?php echo $objResult["card"];?></td>
    <td><?php echo $objResult["name"];?></td>
    <td><div align="center"><?php echo $objResult["username"];?></div></td>
    <td align="right"><?php echo $objResult["password"];?></td>
    <td align="right"><?php echo $objResult["pic"];?></td>
    <td align="center"><?php echo $objResult["room"];?></td>
    <td align="center"><input type="checkbox" name="chkDel[]" id="chkDel<?php echo $i;?>" value="<?php echo $objResult["id"];?>"></td>
  </tr>
<?php
}
?>
</table>


<input type="submit" name="btnDelete" value="Delete">
<input type="hidden" name="hdnCount" value="<?php echo $i;?>">
</form>
<?php
	}
	}else {
		
		echo "<meta http-equiv='Content-Type' content='text/html; charset=UTF-8' />";
		echo "<script language='javascript'>alert('ลบข้อมูล');</script>";
		echo "<meta http-equiv='refresh' content='0;URL=../login/d.php'>";
		
	}
	
	?>