Getting Errors, what do they mean?

[newguyatthis]

i m a new user of smf and recently got my site up, www.respiratorychat.com and i have been seeing these errors in my error log. I added a few tabs in my menu bar ( email, gallery, and cpanel links)
but getting really nervous about these errors. how do i fix?

8: Use of undefined constant cpanel - assumed 'cpanel'
File: /home/respirat/public_html/Themes/default/Admin.template.php (main_above sub template - eval?)
Line: 646

2: memcache_get_version() expects exactly 1 parameter, 0 given
File: /home/respirat/public_html/Sources/Admin.php
Line: 244

cpanel i m guessing is the link to my hosting panel that i put up to show when i m signed in as admin.

thanks