I have a fairly heavily modified UK OSCommerce shop. The modifications make it impossible for me, with my low PHP skill levels, to install an OSCommerce add-on called "Country/State Selector", which creates a drop-down list of states/counties when a customer selects their country from another drop-down list. I think the modification which makes it difficult for me to install this add-on is "Fast Easy Checkout", which changes the same files that "Country/State Selector" wants me to change. But as the files have already been changed by "Fast Easy Checkout", I don't know what to change.
What's happening occasionally, at the moment, is that a customer types info into the "County State" text box, but if that text doesn't match exactly the OSCommerce Zones they get a "please select a state from the States pull down menu" message and cannot complete their purchase until they enter a state which OSCommerce recognises. Some customers contact us about this, but many more abandon their shopping cart and go elsewhere. So it needs fixing. If I could get the "Country/State Selector" add-on working, the county/state would always match the OSCommerce zones and this problem would be solved.
This is the first time I've asked for help here, so I hope I've explained what I want clearly enough. If you need more info please ask.