diff --git a/README.md b/README.md
index bcf27a4..49bbeb2 100644
--- a/README.md
+++ b/README.md
@@ -16,11 +16,49 @@ var ad = vast.attachAd({
       id : 1
     , structure : 'inline'
     , sequence : 99
+    , Error: 'http://error.err'
     , AdTitle : 'Common name of the ad'
     , AdSystem : { name: 'Test Ad Server', version : '1.0' }
   });
 ```
 
+### Ad extensions
+
+```javascript
+var VAST = require('vast-xml');
+
+var vast = new VAST();
+var ad = vast.attachAd({ 
+      id : 1
+    , structure : 'inline'
+    , sequence : 99
+    , Error: 'http://error.err'
+    , Extensions: ['<xml>data</xml>'] // accepts an array or string of XML, warning: XML is not validated by this library!
+    , AdTitle : 'Common name of the ad'
+    , AdSystem : { name: 'Test Ad Server', version : '1.0' }
+  });
+```
+
+### AdVerifications (VAST 4.1)
+
+```javascript
+var VAST = require('vast-xml');
+
+var vast = new VAST({version: '4.1'});
+var ad = vast.attachAd({
+    id : 'AdVerificationsExample'
+    , structure : 'wrapper'
+    , AdSystem : { name : '2.0', version : '2.0' }
+    , Error : 'https://error.url.com/path/p?error=true'
+    , AdVerifications: [{ vendor: 'thirdPartyVendor-com.omid'
+              ,  JavaScriptResource: { browserOptional: 'false', resourceUrl: 'https://path.to/adVerification/script.js'}
+              ,  trackingEvents: [{ event:'verificationNotExecuted', url: 'https://error.url.com/p?event=verificationNotExecuted?' }, {event:'secondEvent', url: 'https://second.url/p?secondEvent=true' }] 
+              ,  VerificationParameters: 'Parameter=one&Parameter=two'
+            }]
+    , VASTAdTagURI : 'https://path.to.original/vast.xml'
+  });
+```
+
 ## Attach Impression tracking URLs
 
 ```javascript
@@ -133,6 +171,7 @@ vast.xml({ pretty : true, indent : '  ', newline : '\n' });
       <AdTitle>Common name of the ad</AdTitle>
       <Description/>
       <Survey/>
+      <Error><![CDATA[http://error.err]]></Error>
       <Impression id="23">http://impression.com</Impression>
       <Impression id="sample-server">http://sample-impression.com</Impression>
       <Creatives>
diff --git a/index.js b/index.js
index 15ae052..3a894c5 100644
--- a/index.js
+++ b/index.js
@@ -16,7 +16,9 @@ var xml = function(options) {
     if (ad.structure.toLowerCase() === 'wrapper') { 
       var wrapper = Ad.element('Wrapper');
       wrapper.element('AdSystem', ad.AdSystem.name, { version : ad.AdSystem.version });
-      wrapper.element('VASTAdTagURI', ad.VASTAdTagURI);
+      wrapper.element('VASTAdTagURI').cdata(ad.VASTAdTagURI);
+      if (ad.Error)
+        wrapper.element('Error').cdata(ad.Error);
       ad.impressions.forEach(function(impression) {
         if (track) wrapper.element('Impression').cdata(impression.url);
       });
@@ -56,7 +58,8 @@ var xml = function(options) {
             icon.element(r.type, r.uri, (r.creativeType) ? { creativeType : r.creativeType } : {});
           });
         });
-        creativeType.element('Duration', c.Duration);
+        //creativeType.element('Duration', c.Duration);
+        creativeType.element('Duration').cdata(c.Duration);
         var trackingEvents = creativeType.element('TrackingEvents');
         c.trackingEvents.forEach(function(trackingEvent){
           if (track) {
@@ -68,7 +71,7 @@ var xml = function(options) {
         if (c.AdParameters) creativeType.element('AdParameters').cdata(c.AdParameters);
         var videoClicks = creativeType.element('VideoClicks');
         c.videoClicks.forEach(function(videoClick){
-          videoClicks.element(videoClick.type, videoClick.url, { id : videoClick.id });
+          videoClicks.element('ClickThrough', videoClick.attributes).cdata(videoClick.url)
         });
         var mediaFiles = creativeType.element('MediaFiles');
         c.mediaFiles.forEach(function(mediaFile) {
@@ -97,6 +100,41 @@ var xml = function(options) {
           if (r.adParameters) companion.element('AdParameters', r.adParameters.data, { xmlEncoded : r.adParameters.xmlEncoded });
         });
       });
+    if (ad.Extensions) {
+      var extensions;
+      if(inline != void 0) extensions = inline.element('Extensions');
+      if(wrapper != void 0) extensions = wrapper.element('Extensions');
+      [].concat(ad.Extensions).forEach(function(extension) {
+        extensions.element('Extension', {type: 'AdVerifications'}).raw(extension);
+      });
+    }
+
+    if (ad.AdVerifications){
+      // VAST 4.1 necessary
+      var adVerifications;
+      if(wrapper != void 0) adVerifications = wrapper.element('AdVerifications');
+
+      [].concat(ad.AdVerifications).forEach(function(currentVerifiction){
+        
+        var ad_verifications = adVerifications.element('Verification', {vendor: currentVerifiction.vendor});
+
+          [].concat(currentVerifiction).forEach(function(verif) {
+            // browserOptional -> true would signify that it's our native script -> e.g. to run in iOS' JSContext
+            // false meaning that the resource needs a true JS environment 
+            ad_verifications.element('JavaScriptResource', {browserOptional: verif.JavaScriptResource.browserOptional}).cdata(verif.JavaScriptResource.resourceUrl);
+
+            if(verif.trackingEvents) {
+              var trackElementsNode = ad_verifications.element('TrackingEvents');
+              var currentTrackingEvent = verif.trackingEvents;
+              [].concat(currentTrackingEvent).forEach(function(currentTrackingEvent){
+                trackElementsNode.element('Tracking', {event: currentTrackingEvent.event}).cdata(currentTrackingEvent.url);
+              });
+            } 
+            ad_verifications.element('VerificationParameters').cdata(verif.VerificationParameters);
+          }); // end of concat each Verification Node
+      });
+    } 
+
   });
   return response.end(options);
 };
diff --git a/lib/ad.js b/lib/ad.js
index ce65f70..ef16a1b 100644
--- a/lib/ad.js
+++ b/lib/ad.js
@@ -40,6 +40,7 @@ function Ad(settings) {
   this.Error = settings.Error;
   this.Description = settings.Description;
   this.Advertiser = settings.Advertiser;
+  this.AdVerifications = settings.AdVerifications; // vast 4.1
   this.surveys = [];
   this.attachSurvey = function(settings) {
     var survey = { url : settings.url }