About Transformation From Test Account To Authorize.net Accoutn

Hi, I'm intrested to use auothorize.net in my website. I  created a test account in that and get login api and tranasaction key. i used those details in my coding and i tested it with test card number. It was working fine and now i have migrated test details with my authorize.net login api and transaction key. Its not working right now. My auothorize.net account is activated. Please look at this page in my server. https://shouldigetmarried.net/tab.php Please fill all the fields with dummy data and you can get the error at end. Please help out from this.   Best Regards,sateesh.