webm:invoke and authentication

Hi,

I’ve a JSP (that uses webm taglib) and I am trying to invoke a webmethods service using webm:invoke.
<webm:invoke serviceName=“myfolder:myservice”>

The service has execute ACL set to ‘Administrator’.

How do I pass the authentication information for this call. I searched the taglib but did not find any attribute for setting the user/password.

Please help.