Some tweaks to style and javascript loading

google_drive/public/css/google_docs.css

 .google-docs-xblock-wrapper iframe{
     max-width: 100%;
-    max-height: 100%;
     display:block;
     margin: 0 auto;
 }
 
-iframe.no-width-height{
+.google-docs-xblock-wrapper iframe.no-width-height{
     top: 0;
     left: 0;
     width: 100%;
@@ -16,7 +15,6 @@ iframe.no-width-height{
     width: auto;
     height : auto;
     max-width: 100%;
-    max-height: 100%;
 }
 
 #validation_alert{

google_drive/public/js/google_docs.js

 /* Javascript for GoogleDocumentBlock. */
 function GoogleDocumentBlock(runtime, element) {
 
-    var iframe = $('iframe', element);
-    var iframe_src = iframe.attr('src');
+    $(function ($) {
+
+        var iframe = $('iframe', element);
+        if(iframe.length > 0){
+            var iframe_src = iframe.attr('src');
 
-    if ((iframe_src.indexOf("document") >= 0) ||
-        (iframe_src.indexOf("spreadsheets") >= 0)){
-        /* add class to iframe containing Google document or spreadsheet*/
-        iframe.addClass('no-width-height');
-    }
+            if ((iframe_src.indexOf("document") >= 0) ||
+                (iframe_src.indexOf("spreadsheets") >= 0)){
+                /* add class to iframe containing Google document or spreadsheet*/
+                iframe.addClass('no-width-height');
+            }
+        }
 
-    $('iframe', element).load(function(){
-        var iframe_url = $(this).attr('src');
-        $.ajax({
-            type: "POST",
-            url: runtime.handlerUrl(element, 'iframe_loaded'),
-            data: JSON.stringify({url: iframe_url})
+        $('iframe', element).load(function(){
+            var iframe_url = $(this).attr('src');
+            $.ajax({
+                type: "POST",
+                url: runtime.handlerUrl(element, 'iframe_loaded'),
+                data: JSON.stringify({url: iframe_url})
+            });
         });
-    });
 
-    $('img', element).load(function(){
-        var image_url = $(this).attr('src');
-        $.ajax({
-            type: "POST",
-            url: runtime.handlerUrl(element, 'image_loaded'),
-            data: JSON.stringify({url: image_url})
+        $('img', element).load(function(){
+            var image_url = $(this).attr('src');
+            $.ajax({
+                type: "POST",
+                url: runtime.handlerUrl(element, 'image_loaded'),
+                data: JSON.stringify({url: image_url})
+            });
         });
-    });
 
-    $(function ($) {
-        /* Here's where you'd do things on page load. */
     });
 }