diff --git a/README.md b/README.md
index 2bb033f..4adebc6 100644
--- a/README.md
+++ b/README.md
@@ -11,14 +11,14 @@
 * After jQuery, either in a `<script>` block or a separate file, call:
 
 ```js
-$('img[usemap]').rwdImageMaps();
+$(window).rwdImageMaps();
 ```
 
 You may also want to wrap it inside a `$(document).ready()` function, like so:
 
 ```js
 $(document).ready(function(e) {
-    $('img[usemap]').rwdImageMaps();
+    $(window).rwdImageMaps();
 });
 ```
 
diff --git a/jquery.rwdImageMaps.js b/jquery.rwdImageMaps.js
index c9d7348..56fa9d3 100644
--- a/jquery.rwdImageMaps.js
+++ b/jquery.rwdImageMaps.js
@@ -9,11 +9,9 @@
 * Licensed under the MIT license
 */
 ;(function($) {
-	$.fn.rwdImageMaps = function() {
-		var $img = this;
-		
-		var rwdImageMap = function() {
-			$img.each(function() {
+    $.fn.rwdImageMaps = function() {
+        var rwdImageMap = function() {
+            $('img[usemap]').each(function() {
 				if (typeof($(this).attr('usemap')) == 'undefined')
 					return;