If having problems placing an order with the shopping cart...

Javascript and cookies must be enabled in your browser for the shopping cart to work.  Enable them and then click the "Back" button to return.
(Click on your browser 'Help' menu, if needed, to get help on setting these.)
Clues to the specific problem:

1. If no shopping cart windows appear, then Javascript is likely disabled in your browser

2. If items don't stay in the shopping cart, then cookies is likely not enabled.