Transactions declined by authrize.net gateway

-- HikaShop version -- : 2.2.0
-- Joomla version -- : 31.15
-- PHP version -- : 5.3.27
-- Error-message(debug-mod must be tuned on) -- : Transaction is declined everytime try to make payment by using authorize.net gateway.

Please help me to sort out the issue, i am using authorize.net gateway, its all set correctly, but i am getting transactions declined all the time, can someone give me some idea on it plz.
thanks,

Hello,
Can you show me how did you configured your authorize.net through some screenshots and more information about the error that you are having if you have one ?
Thanks.