Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in

<?
	if($_GET["txtKeyword"]!= "")
	{
		$keyword = explode(" ", $_GET["txtKeyword"]);
	for($h= 0; $h < count ($keyword); $h++){
	}
	$strSQL = "SELECT register.*,employee.* FROM register LEFT JOIN employee on register.re_id = employee.re_id WHERE register.enable ='T' AND 
	(register.re_busi LIKE '%".$keyword[0]."%')
	and 
	(register.re_busi LIKE '%".$keyword[1]."%')
	and
	(register.re_busi LIKE '%".$keyword[2]."%')
	and
	(register.re_busi LIKE '%".$keyword[3]."%')
	and
	(register.re_busi LIKE '%".$keyword[4]."%')";
	$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
	$Num_Rows = mysql_num_rows($objQuery);


	$Per_Page = 15;   // Per Page

	$Page = $_GET["Page"];
	if(!$_GET["Page"])
	{
		$Page=1;
	}

	$Prev_Page = $Page-1;
	$Next_Page = $Page+1;

	$Page_Start = (($Per_Page*$Page)-$Per_Page);
	if($Num_Rows<=$Per_Page)
	{
		$Num_Pages =1;
	}
	else if(($Num_Rows % $Per_Page)==0)
	{
		$Num_Pages =($Num_Rows/$Per_Page) ;
	}
	else
	{
		$Num_Pages =($Num_Rows/$Per_Page)+1;
		$Num_Pages = (int)$Num_Pages;
	}

$strSQL .=" order  by em_id ASC LIMIT $Page_Start , $Per_Page";
$objQuery  = mysql_query($strSQL);
?>

    <form name="frmMain" action="employee_delete.php" method="POST" onSubmit="return onDelete();">
	<input type="hidden" name="hdnCount" value="<?=$s;?>">
	<table width="80%" border="1" cellspacing="0" >
	  <tr bgcolor="orange" class="style1">
      	<th><input type="image" src="delete.png" name="btnDelete" value="Delete" alt="ลบ" width="20" height="20"></th>
		<th> <div align="center">ชื่อบริษัท</div></th>
		<th> <div align="center">ชื่อ</div></th>
		<th> <div align="center">นามสกุล</div></th>
		<th> <div align="center">ตำแหน่ง</div></th>
        <th> <div align="center">สัญญาเริ่ม</div></th>
        <th> <div align="center">หมดสัญญา</div></th>
        <th> <div align="center">แก้ไข</div></th>
	  </tr>
	<?
	while($objResult = mysql_fetch_array($objQuery))
	{
		if($bg == "white")
		{
			$bg = "#FFFF99";
		} 
	else
		{
				$bg = "white";
		}
	?>
	  <tr bgcolor="<?=$bg;?>" class="style5">
      	<td align="center"><input type="checkbox" name="chkDel[]" id="chkDel<?=$s;?>" value="<?=$objResult['em_id'];?>"></td>
		<td align="center">
        <input type="hidden" name="em_id" value="<?=$objResult['em_id'];?>" />
		<?=$objResult['re_busi'];?>
        </td>
		<td>
		<?=$objResult['em_name'];?>
        </td>
		<td >
		<?=$objResult['em_lastname'];?>
        </td>
        <td align="center">
		<?=$objResult['em_position'];?>
        </td>
        <td align="center">
		<?=$objResult['em_first'];?>
        </td>
        <td align="center">
		<?=$objResult['em_last'];?>
        </td>
        <td align="center"><a href="employee_edit.php?em_1=<?=$objResult["em_id"];?>">แก้ไข</a></td>
	  </tr>
	<?PHP
	}
	?>
	</table>
    </form>

	mysql_close($objConnect);
	}
	?>