Payment method currency, undefined index error

HI
I have installed the extensionit but keep getting error message:
Notice: Undefined index: action in /customers/e/d/d/website.com/httpd.www/admin/controller/module/payment_currency.php on line 14Warning: Cannot modify header information - headers already sent by (output started at /customers/e/d/d/website.com/httpd.www/admin/index.php:80) in /customers/e/d/d/website.com/httpd.www/system/library/response.php on line 12

I'm not a programmer and have no idea what to change in payment_currency.php. Anyone experienced the same?