Simple Update inside while loop

[shadowmax]

Im making a cron job and currently it diplays the result correctly but when it needs to update it fails.
Anyone have any ideas

<?php


//phpinfo();
$mysqli = new mysqli('-','-','-', "-");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}


$result2 = "SELECT * FROM tblJobs order by DatePosted desc";
$result = mysqli_query($mysqli, $result2)
or die('Error querying database.');


while($row = mysqli_fetch_array($result))
  {
    
    
$time = strtotime($row['DatePosted']);
$one_week_ago = strtotime('-30 days');

if( $time > $one_week_ago ) { 

    
}else{

echo "<td>needs hiding</td>";    
$tempff = $row['JobID'];

$update = "UPDATE tblJobs SET Show = 0 WHERE JobID = ".$row['JobID']."";
$result = mysqli_query($mysqli, $update);
    
}


  }




?>