I know its been so long and probably wont be answered but I need to add a option to the product where they can enter there own size for the product.
I'm listing filter sizes but if there isn't one i'd like the customer to choose a custom size and add a extra charge and let them post there size??????

The shopping cart has been discontinued so there won't be anymore updates.

Hi Louis,

Eric is correct but I do have a work around. Do you own Webform Builder? If not i would consider getting it here: http://www.coffeecup.com/web-form-builder/

I would create a custom form then in the description of your products you can add a link to your form telling them if they can't find their size to click on link to order custom. This will take them to your form were they can fill out all the info you need to complete the order.