Getting error while on checkout page

Hi..!

I just set up my site..and I am getting problem on checkout page as using the perfect money woocommerce payment gateway plugin..the error is as :

{"result":"failure","messages":"
\n
\n
\n\t

    \n\t\t\t\t\t
    Country<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    First Name<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    Last Name<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    Address<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    Town \/ City<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    Postcode \/ Zip<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    Email Address<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    Phone<\/strong> is a required field.<\/li>\n\t\t\t\t\t
    Invalid payment method.<\/li>\n\t\t\t<\/ul>\n<\/div>\n<\/div>\n<\/div>","refresh":"false","reload":"false"}

Here is Perfect Money Woocommerce Payment Gateway Plugin Index.php link : http://pastebin.com/vmS8Qgrf

Please let me know..what is causing this error..and how to solve it…
Waiting for your replies…!

Regards,