Fatal error message…please help

i don’t know why..but when ever i try to access my admin dashboard i get the following error message:

Fatal error: Call to undefined function get_option() in /home/a9776328/public_html/wp-admin/admin.php on line 9

and when i try to access the main page of the site i get this error message:

Fatal error: Call to undefined function wp() in /home/a9776328/public_html/wp-blog-header.php on line 14

please guys…i need help

thanx in advance