Cost of Freedom Text Based App

cof.php

<?php
  header('Content-type: text/xml');
  echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
  $message = strip_tags($_REQUEST['Body']);
  $response =  "Welcome to the Cost of Freedom. Please text your state abbreviation to get Voter ID requirements and info.";

  //our spreadsheet's key
  $key = "0Aoz1Ir-h-0g5dG00N1lDVG1COTFHellrc2o2bDhoeXc";

  //the public url        
  $url = "http://spreadsheets.google.com/feeds/cells/$key/1/public/values";
          
  $ch = curl_init();

  //set some curl options 
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_HEADER, 0);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
         
  $google_sheet = curl_exec($ch);
         
  curl_close($ch);
      
  $doc = new DOMDocument();
  $doc->loadXML($google_sheet);
  //for each state, we load in the appropriate cell from the spreadsheet and then print out the text within
  $states = array(
    'AL' => 5,
    'AK' => 8,
    'AZ' => 11,
    'AR' => 14,
    'CA' => 17,
    'CO' => 20,
    'CT' => 23,
    'DE' => 26,
    'DC' => 29,
    'FL' => 32,
    'GA' => 35,
    'HI' => 38,
    'ID' => 41,
    'IL' => 44,
    'IN' => 47,
    'IA' => 50,
    'KS' => 53,
    'KY' => 56,
    'LA' => 59,
    'ME' => 62,
    'MD' => 65,
    'MA' => 68,
    'MI' => 71,
    'MN' => 74,
    'MS' => 77,
    'MO' => 80,
    'MT' => 83,
    'NE' => 86,
    'NV' => 89,
    'NH' => 92,
    'NJ' => 95,
    'NM' => 98,
    'NY' => 101,
    'NC' => 104,
    'ND' => 107,
    'OH' => 110,
    'OK' => 113,
    'OR' => 116,
    'PA' => 119,
    'RI' => 122,
    'SC' => 125,
    'SD' => 128,
    'TN' => 131,
    'TX' => 134,
    'UT' => 137,
    'VT' => 140,
    'VA' => 143,
    'WA' => 146,
    'WV' => 149,
    'WI' => 152,
    'WY' => 155
  );
  if (in_array($message, $states)) {
    $node = $doc->getElementsByTagName("cell")->item($states[$message]);
    $response = $node->textContent; 
  }
?>
<Response>
<Sms><?php echo $response; ?></Sms>
</Response>