Changing landing page at login

Greetings - by default, the landing page at login is "activity", but I'd like to have members land on their "groups" page instead.  I see in the index.php code where the landing page is set, but am not familier with PHP coding and I want the landing page to be the "My Groups" page - i.e. elgg/groups/member/admin.  How can I modify the index.php to make this happen?

Thanks - John