using ivy publish artifacts to nexus repo

[Giridharan Kesavan]

I'm tryin to publish artifacts to my internal nexus repo:

Here is the exception I get while doing so
java.io.IOException: Access to URL 
http://<host>/nexus/content/repositories/releases/[organisation]/[revision]/[artifact].[ext]
 was refused by the server: Unauthorized

ivy:configure task:

<ivy:configure settingsid="${ant.project.name}.ivy.settings" 
file="${ivysettings.xml}" override='true'
      host="${hostname}" realm="Sonatype Nexus Repository Manager" 
username="user" passwd="password"/>

Let me know if Im missing something..

Thanks,
Giri