Error in Joomla backend menu operations

I am getting following error with most of the menus and links from the control penal in the joomla backend: There is no issue with frontend. Can you please guide me how can i sort it out.

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 22

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 23

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/menu.php on line 94

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 28

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/menu.php on line 94

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 34

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 39

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 40

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/menu.php on line 94

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 46

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 56

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 60

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 64

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 70

Notice: Only variables should be passed by reference in /home4/pawanhg/public_html/asklaw.in/administrator/modules/mod_menu/tmpl/default_enabled.php on line 74