u have to impersonate the authorized credentials thorgh ur code

That was my question ,i tried using the following code ,but it did not work
Can u provide me with code snippet

The 2 ways i tried were this
1.By using default one
ContactManagementWebServices.Lists lists= new
ContentManagement.ContactManagementWebServices.Lists();
lists.UseDefaultCredentials = true;
lists.Credentials = System.Net.CredentialCache.DefaultCredentials;

2.
NetworkCredential networkCredential = null;
UserCredential userCredential = UserCredential.GetInstance();
networkCredential = userCredential.NetworkCred;
In which i provided the user id ,pwd and domain

I think we cannot use Net credentials as it not windows based authentication  but
is form based