function to get time difference

	function get_days($row)
	{
		$diff = strtotime($row['duedate']) - strtotime(date('Y-m-d'));
		$diff_days = floor($diff/(60*60*24));
		$html = abs($diff_days)<10000 ? '<td>'.$diff_days.'</td>' : '<td> </td>';
		return $html;
	}