delegation with sunbird question

[michael.laengle]

Hi Guys i have one question to delegation e.g.
michael delegates his calendar (manager rights) to pascal
then pascal creates his own calendar in sunbird e.g.:
http://pascal:hispassword@zimbra.uni...ascal/Calendar
then he creates an additional calendar (the calendar of michael)
http://zimbra.uni-konstanz.de/dav/michael/Calendar

it seems to work fine but only when pascal saves his userid/password in the caldav url of sunbird.
Is there an way to avoid this?
Thanks Michael