Please never, ever give your password to anyone for any reason. LiveJournal will never ask you for your password via email, or for any reason other than to log into LiveJournal. You should never enter your password into a form on your friends page, or on a site that doesn't belong to LiveJournal.
If you are interested in customizing your journal, see the LiveJournal FAQ, specifically the "Customization" category. If you've entered your username and password into a form like this, please change your password immediately.