How to get "AuthSub " token in C#? For google APPS Contacts ?

Question

Hi,

I fount this code on net :

HttpWebRequest update = (HttpWebRequest)WebRequest.Create(**editUrl** );  // editUrl is a string containing the contact's edit URL
update.Method         = "PUT";
update.ContentType    = "application/atom+xml";
update.Headers.Add(HttpRequestHeader.Authorization, "GoogleLogin auth=" + **AuthToken**);
update.Headers.Add(HttpRequestHeader.IfMatch, **etag**);  // etag is a string containing the <entry> element's gd:etag attribute value

update.Headers.Add("GData-Version", "3.0");

Stream streamRequest      = update.GetRequestStream();
 StreamWriter streamWriter = new StreamWriter(streamRequest, Encoding.UTF8);
streamWriter.Write(entry);  // entry is the string representation of the atom entry to update
streamWriter.Close();
WebResponse response      = update.GetResponse();  

But here i am not getting what to put in " editurl" , "AuthToken" and "Etag".

a) I studied abt "AuthToken" from this Link .But not getting how to create it? Can anyone help me out here?

b) Also not getting " editurl" and "Etag".

I am trying to use this method to Migrate my contacts to Google Apps.

Thanx