มันขึ้น script หยุดทำงาน ดูด้านในครับช่วยหน่อยคร้าบบบบบ

public function addbackup()
		{
			$tables = '*';
			connectdatabase();
			date_default_timezone_set("Asia/Bangkok");
			$date = date("Y-m-d");
			$sql = "select * from backup where Bu_date='".$date."'";
			$rs = mysql_query($sql);
			$num = mysql_num_rows($rs);
			if($num == 0)
			{
				$sql = "select * from backup order by Bu_id DESC limit 1";
				$rs = mysql_query($sql);
				$num = mysql_num_rows($rs);
				if($num == 0)
					$id = 1;
				else
					while($row = mysql_fetch_object($rs))
						$id = $row->Bu_id + 1;

				//$sql = "insert into backup (Bu_id , Bu_date) values ('".$id."','".$date."')";
				//mysql_query($sql);

				//get all of the tables
				if($tables == '*')
				{
				  	$tables = array();
					$result = mysql_query('SHOW TABLES');
				    while($row = mysql_fetch_row($result))
				    {
				      $tables[] = $row[0];
				    }
				}
				else
				{
				    $tables = is_array($tables) ? $tables : explode(',',$tables);
				}
				  
				//cycle through
				foreach($tables as $table)
				{
				    $result = mysql_query('SELECT * FROM '.$table);
				    $num_fields = mysql_num_fields($result);
				    
				    $return.= 'DROP TABLE '.$table.';';
				    $row2 = mysql_fetch_row(mysql_query('SHOW CREATE TABLE '.$table));
				    $return.= "\n\n".$row2[1].";\n\n";
				    
				    for ($i = 0; $i < $num_fields; $i++) 
				    {
				    	while($row = mysql_fetch_row($result))
				      	{
				        	$return.= 'INSERT INTO '.$table.' VALUES(';
				        	for($j=0; $j<$num_fields; $j++) 
				        	{
				         		$row[$j] = addslashes($row[$j]);
				          		$row[$j] = ereg_replace("\n","\\n",$row[$j]);
				          		if (isset($row[$j])) { $return.= '"'.$row[$j].'"' ; } else { $return.= '""'; }
				          		if ($j<($num_fields-1)) { $return.= ','; }
				        	}
				        	$return.= ");\n";
				      	}
				    }
				    $return.="\n\n\n";
				}
				
				$date = date("d-m-Y" , strtotime($date));
				//save file
				$handle = fopen('../tmp/db-resinart'.$date.'.sql','w+');
				fwrite($handle,$return);
				fclose($handle);

				echo "<script>window.location.reload()</script>";
			}
			else
			{
				echo "<span style='color:red'>ไม่สามารถ backup ข้อมูลได้ เนื่องจากวันนี้ได้ทำการ backup แล้ว</span>";
			}