PHP - When There Is No Value In A Cell

<select name="ad_type">
	<option selected="selected"><?php echo $post['ad_type']; ?></option>
	<option>-- Please Select --</option>
	<option value="For Adoption">For Adoption</option>
	<option value="For Sale">For Sale</option>
</select>

 <?php
			
			$sql="SELECT product_id FROM Products";
			$query=mysql_query($sql);
			$row=mysql_fetch_array($query);
			
			
	 ?><table >
          
	 
	 				<tr><img src="Images/Image.jpg" width="380" height="300" /> </tr>
                    <tr>
						
						
						<td><a href="index.php?page=index&action=add&id=<?php echo $row['product_id']?>">Add to cart</a></td>
						
						</tr>
    <?php
			
		
     ?>
        </table>
       

Hi there

I have started using php excell and getting most of it right. 

But i am struggling to search active sheet and return what cell the string is in. below is my code.

<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
set_time_limit(0);



$directory = "/var/www/html/csvex/xls/";
$formatdirectory = "/var/www/html/csvex/toformat/";
$finishedformatdirectory = "/var/www/html/csvex/formatted/";
$savanadirectory = "/var/www/html/iretire/files/upload/1/";
$main = "/var/www/html/csvex/";


$files = scandir($directory, SCANDIR_SORT_DESCENDING);

$newest_file = $files[0];
echo $newest_file;
echo "<br>";
$oldfile = $directory.$newest_file;
$newfile = $formatdirectory.$newest_file;
$changedfile = $finishedformatdirectory.$newest_file;
$crmfile = $savanadirectory.$newest_file;
echo $oldfile;
echo "<br>";
echo $newfile;

echo "<br>";
if( !rename($oldfile, $newfile) ) {  
    echo "File can't be moved!";  
}  
else {  
    echo "File has been moved!";  
} 
//format the file


date_default_timezone_set('Europe/London');
set_include_path(get_include_path() . PATH_SEPARATOR . './Classes/');

include 'PHPExcel/IOFactory.php';

$fileType = 'Excel5';
$fileName = $newfile;

// Read the file
$objReader = PHPExcel_IOFactory::createReader($fileType);
$objPHPExcel = $objReader->load($fileName);
//change font
$objPHPExcel->getActiveSheet()->getStyle('a1:a6')->applyFromArray(
$styleArray = array(
'font' => array(
'bold' => true
)
)
);
$objPHPExcel->getActiveSheet()->getStyle('a6:aa6')->applyFromArray(
$styleArray = array(
'font' => array(
'bold' => true
)
)
);
$objPHPExcel->getActiveSheet()->getStyle('n16:aa16')->applyFromArray(
$styleArray = array(
'font' => array(
'bold' => true
)
)
);
//get INACTIVE MEMBERS
$foundInCells = array();
$searchValue = 'INACTIVE MEMBERS';
foreach ($objPHPExcel->getActiveSheet() as $worksheet) {
    $ws = $worksheet->getTitle();
    foreach ($worksheet->getRowIterator() as $row) {
        $cellIterator = $row->getCellIterator();
        $cellIterator->setIterateOnlyExistingCells(true);
        foreach ($cellIterator as $cell) {
            if ($cell->getValue() == $searchValue) {
                $foundInCells[] = $ws . '!' . $cell->getCoordinate();
            }
        }
    }
}
echo "<br>";
echo "<br>";
echo "this is where - - ";
var_dump($foundInCells);
echo "<br>";
echo "<br>";
//
$objPHPExcel->getActiveSheet()->getStyle('a20')->applyFromArray(
$styleArray = array(
'font' => array(
'bold' => true
)
)
);

its located at //Get inactive members.

another one i am struggling with is to see if file exists if not then do nothing if it does run the code.