Example of the html code from Pay Pal:
<form target="paypal"
action="https://www.paypal.com/cgi-bin/webscr"
method="post">
<input type="image" src="https://www.sandbox.paypal.com/
en_US/i/btn/x-click-but22.gif"
border="0" name="submit" alt="Make payments with PayPal -
it's fast, free and secure!>
<img alt="" border="0"
src="https://www.paypal.com/en_US/i/scr/pixel.gif
width="1" height="1">
<input type="hidden" name="add" value="1">
<input type="hidden" name="cmd" value="_cart">
<input type="hidden" name="business"
value="
[email protected]">
<input type="hidden" name="item_name"
value="Store Item 1">
<input type="hidden" name="amount" value="50.00">
<input type="hidden" name="no_shipping" value="2">
<input type="hidden" name="no_note" value="1">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="tax" value="0">
<input type="hidden" name="bn" value="IC_Sample">
</form>