[ic] Quick order - Enter an SKU into a form

[Chris Rapier]

I'm trying to write a page where the user can simply enter an SKU into a
form and have that automatically added to their cart. I've got it
working for the most part except...

I give them 10 fields they can enter skus into. If they leave an sku
field blank it adds a 'null' entry into their shopping cart. I can
delete this by setting the quanitity to zero but it would be better if
it never entered the item into the shopping cart in the first place. I
had assumed that an order item without an sku woudl simply be ignored
but this is not the case. This is under minivend 4 but I'm guessing
similar problems would arise under interchange.

Any suggestions?