HTML
<html>
<head>
<title>Merchant Weborm</title>
</head>
<body>
<h1>Merchant XYZ</h1>
<p>Customer Checkout</p>
<form method="post" action="https://<Hosted Payments Url>">
<input name="hp_merchant_id" type="hidden" value="your merchant id" />
<input name="hp_txntype" type="hidden" value="sale" />
<input name="hp_amount" type="hidden" value="100.00" />
<input name="hp_method" type="hidden" value="ccard" />
<input name="hp_cardnum" type="hidden" value="4111111111111111" />
<input name="hp_expmonth" type="hidden" value="12" />
<input name="hp_expyear" type="hidden" value="2021" />
<input name="hp_bname" type="hidden" value="Joe Consumer" />
<input name="hp_baddr" type="hidden" value="123 Main St." />
<input name="hp_bcity" type="hidden" value="Moorpark" />
<input name="hp_bstate" type="hidden" value="CA" />
<input name="hp_bcountry" type="hidden" value="US" />
<input name="submit" type="submit" />
</form>
</body>
</html>