show basket directly

[Guest]

I want to generate a 'buy now' button on an external website (not the shop's URL) which puts an item into the shop's basket and shows the basket directly (in a new window) ready for check out.

My imagination is: it must be something like <form action="http://myshop.com/cart.php" method=POST> as the URL to call. But then there must be some hidden fields telling the cart.php what to display.

Any help is welcome!

Thanks.

[Guest]

It is more like this:

<a href=\"http://www.YOUR_URL.com/view_cart.php?add=PRODUCT_ID_HERE&quan=1\"><img src='WHERE_EVER.COM/_YOUR_IMAGE_IS_LOCATED.JPG'></A>