Error message

• Notice: Undefined property: stdClass::$field_author_name in ipress_username() (line 123 of /var/www/vhosts/postwave.gr/httpdocs/sites/all/themes/ipress/template.php).
• Notice: Undefined index: und in include() (line 21 of /var/www/vhosts/postwave.gr/httpdocs/sites/all/themes/ipress/tpl/node--article.tpl.php).
• Notice: Undefined variable: comment_count in include() (line 21 of /var/www/vhosts/postwave.gr/httpdocs/sites/all/themes/ipress/tpl/node--article.tpl.php).