Adding a photo to "Lets Tweet in Unity" plugin

Hi everyone, been trying to figure this out but cannot get it. Im new to unity and am only learning JS, this is in C#. Can anyone help me get https://upload.twitter.com/1/statuses/update_with_media.xml to work?

 private static readonly string PostTweetURL = "http://api.twitter.com/1/statuses/update.xml?status={0}";
 
         public static IEnumerator PostTweet(string text, string consumerKey, string consumerSecret, AccessTokenResponse response, PostTweetCallback callback)
         {
             if (string.IsNullOrEmpty(text) || text.Length > 140)
             {
                 Debug.Log(string.Format("PostTweet - text[{0}] is empty or too long.", text));
 
                 callback(false);
             }
             else
             {
                 string url = string.Format(PostTweetURL, UrlEncode(text));
                 Dictionary<string, string> parameters = new Dictionary<string, string>();
 
                 parameters.Add("status", text);                    
 
                 // Need to fill body since Unity doesn't like an empty request body.
                 byte[] dummmy = new byte[1];
                 dummmy[0] = 0;
 
                 // HTTP header
                 Hashtable headers = new Hashtable();
                 headers["Authorization"] = GetHeaderWithAccessToken("POST", url, consumerKey, consumerSecret, response, parameters);
 
                 WWW web = new WWW(url, dummmy, headers);
                 yield return web;
                 ...