Responsive HTML credit card payment form (JS) Beautiful, stylish design. Fast and high-quality form of payment, written in html, css and javaScript. How is payment done online? Let's analyze step by step how an online payment takes place: The seller (online store) issues an invoice for payment. The buyer enters their banking or other payment details (for example, e-wallet details) in the payment form. The bank or payment provider checks the availability of funds to complete the transaction.