wp-admin login problem

Hi, I get this message when I try to enter the wp-admin login page:

Deprecated: Assigning the return value of new by reference is deprecated in /customers/indadvendt.dk/indadvendt.dk/httpd.www/wordpress/wp-includes/cache.php on line 36

Deprecated: Assigning the return value of new by reference is deprecated in /customers/indadvendt.dk/indadvendt.dk/httpd.www/wordpress/wp-includes/query.php on line 21

Deprecated: Assigning the return value of new by reference is deprecated in /customers/indadvendt.dk/indadvendt.dk/httpd.www/wordpress/wp-includes/theme.php on line 507

Warning: Cannot modify header information – headers already sent by (output started at /customers/indadvendt.dk/indadvendt.dk/httpd.www/wordpress/wp-includes/cache.php:36) in /customers/indadvendt.dk/indadvendt.dk/httpd.www/wordpress/wp-includes/pluggable.php on line 329

I need to update my wordpress version – but I must login before updating. I have no clue how to make the login site work.

Hope to hear from someone,
best regards – majken