Hi,
Thanks to all who responded. What I was having trouble with was I am building a custom shopping cart. As in a lot of carts, I have an update cart function that allows the user to change the quantity of the items and then update the cart contents. The form was dynamically generated and for whatever reason, my own code as it turned out, I was not capturing the changes the user was making. It was simply a missing piece of code in one of my include files. I don't think I would have used javascript for this because of the possibility of the user having javascript turned off, although I know this is all that common.
Anyway, as always, thanks everyone for their help.
Cheers
Dave