What should be in robots.txt?

[Elite_360_]

this is what i have on my site i have it on the root of my site my front end uses joomla

here a link about robots txt

User-agent: *
Disallow: /administrator/
Disallow: /cache/
Disallow: /components/
Disallow: /images/
Disallow: /includes/
Disallow: /language/
Disallow: /libraries/
Disallow: /media/
Disallow: /modules/
Disallow: /plugins/
Disallow: /templates/
Disallow: /tmp/
Disallow: /forum/admincp/
Disallow: /forum/clientscript/
Disallow: /forum/cpstyles/
Disallow: /forum/customavatars/
Disallow: /forum/customprofilepics/
Disallow: /forum/images/
Disallow: /forum/includes
Disallow: /forum/modcp/
Disallow: /forum/ajax.php
Disallow: /forum/attachment.php
Disallow: /forum/calendar.php
Disallow: /forum/cron.php
Disallow: /forum/editpost.php
Disallow: /forum/global.php
Disallow: /forum/image.php
Disallow: /forum/inlinemod.php
Disallow: /forum/joinrequests.php
Disallow: /forum/login.php
Disallow: /forum/member.php
Disallow: /forum/memberlist.php
Disallow: /forum/misc.php
Disallow: /forum/moderator.php
Disallow: /forum/newattachment.php
Disallow: /forum/newreply.php
Disallow: /forum/newthread.php
Disallow: /forum/online.php
Disallow: /forum/poll.php
Disallow: /forum/postings.php
Disallow: /forum/printthread.php
Disallow: /forum/private.php
Disallow: /forum/profile.php
Disallow: /forum/register.php
Disallow: /forum/report.php
Disallow: /forum/reputation.php
Disallow: /forum/search.php
Disallow: /forum/sendmessage.php
Disallow: /forum/showgroups.php
Disallow: /forum/subscription.php
Disallow: /forum/threadrate.php
Disallow: /forum/usercp.php
Disallow: /forum/usernote.php