Added missing file for "Bug in Firefox: Remote XMLHttpRequest" example

shared/json_echo.php

@@ -0,0 +1,68 @@
+<?PHP?><?
+
+// 
+// Simple PHP JSON/P Echo - "Cowboy" Ben Alman - http://benalman.com/
+// v1.0 - 2/20/2009
+// 
+
+// Show script source if no params are passed
+if (count($_GET) == 0) {
+  highlight_file($_SERVER['SCRIPT_FILENAME']);
+  die;
+}
+
+// Get request params
+$obj = array();
+foreach ($_GET as $key => $value) {
+  $obj[$key] = $value;
+}
+foreach ($_POST as $key => $value) {
+  $obj[$key] = $value;
+}
+
+$json_string = isset($obj['JSON']) ? $obj['JSON'] : null;
+$jsonp_callback = isset($obj['callback']) ? $obj['callback'] : null;
+
+// remove misc unneeded params
+unset($obj['_']);
+unset($obj['callback']);
+unset($obj['JSON']);
+
+$json = $json_string ? $json_string : json_encode($obj);
+$jsonp = $jsonp_callback ? $jsonp_callback . "($json)" : $json;
+
+
+sleep(1); // simulate slow connection :D
+
+
+$is_xhr = isset($_SERVER['HTTP_X_REQUESTED_WITH']) &&
+            strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest';
+
+$is_referer = isset($_SERVER["HTTP_REFERER"]);
+
+if ($is_xhr) {
+
+  header( 'Content-type: application/json' );
+  print $jsonp;
+
+} else if ($is_referer) {
+
+  $params = array();
+  foreach ($obj as $key => $value) {
+    $params[] = urlencode($key) . '=' . urlencode($value);
+  }
+
+  $url = preg_replace('/\?.*$/', '', $_SERVER["HTTP_REFERER"]);
+  $url .= '?' . implode('&', $params);
+
+  header( "Location: $url");
+
+} else {
+
+  header( 'Content-type: text/plain' );
+
+  print $jsonp;
+
+}
+
+?>