http post help

<?php

$API_URL = "http://randomcpaoffer.com";

function rest_helper($url, $params = null, $verb = 'GET', $format = 'json') {
  $cparams = array(
    'http' => array(
      'method' => $verb,
      'ignore_errors' => true
    )
  );
  if ($params !== null) {
    $params = http_build_query($params);
    if ($verb == 'POST') {
      $cparams['http']['content'] = $params;
    } else {
      $url .= '?' . $params;
    }
  }

  $context = stream_context_create($cparams);
  $fp = fopen($url, 'rb', false, $context);
  if (!$fp) {
    $res = false;
  } else {
    
    $res = stream_get_contents($fp);
  }

  if ($res === false) {
    throw new Exception("$verb $url failed: $php_errormsg");
  }

  switch ($format) {
    case 'json':
      $r = json_decode($res);
      if ($r === null) {
        throw new Exception("failed to decode $res as json");
      }
      return $r;
    case 'xml':
      $r = simplexml_load_string($res);
      if ($r === null) {
        throw new Exception("failed to decode $res as xml");
      }
      return $r;
  }
  return $res;
}
     
if (isset($_POST['firstname'])) {
    $res = rest_helper($API_URL,
        array(
        'track' => $_POST['track'],
        'First Name' => $_POST['firstname'],
        'Last name' => $_POST['lastname'],
        'email' => $_POST['email']
        'ip' => $_POST['ip'],
    ), 'POST');
    if ($res->result == "success") {
        header("Location: {$res->login*****");
        exit();
    }
}
?>

<? 
if ($res->error_list) {
    print "Please correct the following errors:<br>";
    foreach ($res->error_list as $api) {
        print "$api<br>";
    }
}
?>
<form method='post'>
<input type='hidden' name='track' value='default'>

<h3>Sign Up</h3>
First Name: <input type='text' name='firstname' value='johnsmith'><br>
Last Name: <input type='text' name='password' value='jsmith'><br>
Email Address: <input type='text' name='password' value='[email protected]'><br>
<br>
IP: <input type='text' name='ip' value='111.111.111.111'><br>
<br>
<input type='submit'>
</form>

if ($res->result == "success") {
        header("Location: {$res->login*****");
        exit();
    }

if ($res->result == "success") {
        // need a variable for each piece of data, so just add variables
        $fName = $_POST['firstname'];
        $email = $_POST['email'];
        
        // dependant on your database structure; add fields/values as needed
        mysql_query("INSERT INTO `storage` (`first_name`,`email`) VALUES ('$fName','$email')");
        header("Location: {$res->login*****");
        exit();
    }