I have a client that wants a pay button on their site that will direct their clients to a payment page hosted by authorize.net where a invoice number, dollar amount, and other needed info can be entered to process a payment. They have referenced a couple of sites that appear to use Authorize.net's "Simple Checkout" service (their pay buttons submit a "linkID" to https://Simplecheckout.authorize.net/payment/CatalogPayment.aspx). However, my reading of the Simple Checkout documentation states that the payment button must be registered with authorize.net with a specific dollar amount and the documentation makes no mention of setting up a web-based form on authorize.net.
From my reading of the authorize.net information, it appears that the Simple Integration Method (SIM) or something similar is needed, integrated using serer-side scripting. Is there a simple payment button method that I'm missing that would enable a simple form, hosted by authorize.net, that will allow the user to enter the payment amount along with their payment (credit card) information?
