1<?php
 2  $data =& $_POST;
 3  if (!empty ($data)) {
 4    if (isset($data['date']) &&
 5        isset($data['price']) &&
 6        isset($data['gallons']) &&
 7        isset($data['odometer'])) {
 8      
 9      $file = 'data/lastodo';
10      $lastodo = unserialize(file_get_contents($file));
11    
12      echo 'Added:'.
13           'Date: ' . $data['date'] . ',' .   
14           'Price: ' . $data['price'] . ',' .   
15           'Gallons: ' . $data['gallons'] . ',' .   
16           'Odometer: ' . $data['odometer']. ',' .
17           'Miles = '.((int)$data['odometer'] - (int)$lastodo). '<br />';
18      
19      $lastodo = serialize($data['odometer']);
20      file_put_contents($file, $lastodo);
21
22    } else {
23      echo "missing values\n";
24    }
25  } else {
26      echo "empty form";
27  }
28?>