From within the transaction options, a merchant can enable Test Mode.  Test Mode allows you to process transactions without the transactions being processed in a live environment.  When your account is in test mode, all transactions will be approved.

When in Test Mode, the reporting section will only list transactions processed in Test Mode. These transactions will NOT show up when you are not in Test Mode.

To Enable Test Mode
Click on "ENABLE Test Mode" to enable test mode for your account.

To Disable Test Mode
Click on "DISABLE Test Mode" to disable test mode for your account.