With Paypal, you can sign up for sand box api credentials, then set the Use Sand Box setting in the server behavior that processes transactions. For Authorize.net, there is a test request setting that sends a test transaction.
Thank Jason but I am currently developing my online store app and do not have access to Authorize.net nor do I want to pay there fees unitil I am really ready to test the credit card authorization. however I would like to simulate as though I had process the cc transaction via ecart so I can validate the database updates that ecart would make and my updates. Is there a dummy script I could use to simulate the ecart authorization part? ANy other suggestions?