diff --git a/sites/all/themes/dmtheme/template.php b/sites/all/themes/dmtheme/template.php
index fd4ab0a..aabab7b 100644
--- a/sites/all/themes/dmtheme/template.php
+++ b/sites/all/themes/dmtheme/template.php
@@ -34,3 +34,56 @@ function dmtheme_preprocess_block(&$vars) {
     //
 }
 
+/**
+ * Implements hook_file_url_alter().
+ *
+ * Make all URLs be protocol relative.
+ * Note: protocol relatice URLs will cause IE7/8 to download stylesheets twice.
+ */
+function dmtheme_file_url_alter(&$url) {
+
+  global $base_url;
+
+  static $relative_base_url = NULL, $relative_base_length = NULL;
+
+  $scheme = file_uri_scheme($url);
+
+  // For some things (e.g., images) hook_file_url_alter can be called multiple
+  // times. So, we have to be sure not to alter it multiple times. If we already
+  // are relative protocol we can just return.
+  // Only setup the and parse this stuff once.
+  if (!$relative_base_url || !$relative_base_length) {
+    $relative_base_url = '//' . file_uri_target($base_url);
+    $relative_base_length = strlen($relative_base_url);
+  }
+  if (!$scheme && substr($url, 0, $relative_base_length) == $relative_base_url) {
+    return;
+  }
+
+  // Handle the case where we have public files with the scheme public:// or
+  // the case the relative path doesn't start with a /. Internal relative urls
+  // have the base url prepended to them.
+  if (!$scheme || $scheme == 'public') {
+
+    // Internal Drupal paths.
+    if (!$scheme) {
+      $path = $url;
+    }
+    else {
+      $wrapper = file_stream_wrapper_get_instance_by_scheme($scheme);
+      $path = $wrapper->getDirectoryPath() . '/' . file_uri_target($url);
+    }
+
+    // Clean up Windows paths.
+    $path = str_replace('\\', '/', $path);
+
+    $url = $base_url . '/' . $path;
+  }
+
+  // Convert full URLs to relative protocol.
+  $protocols = array('http', 'https');
+  $scheme = file_uri_scheme($url);
+  if ($scheme && in_array($scheme, $protocols)) {
+    $url = '//' . file_uri_target($url);
+  }
+}