<form method="post" action=
"https://cartmanager.net/cgi-bin/cart.cgi">
Name: <input type="text" name="VARname" />
<input type="hidden" name="AddItem" value="demo|Demo Product Name: VARname|4.95|1||||||||||" />
<input type="submit" value="Add To Cart" alt="Add to cart"/>
</form>