I have a fully working custom form to take bulk orders. However, I have hardcoded the dropdown for the products we have in our store. But it is becoming apparent that this is becoming a choir when we take items off the site as active. Is their a function built in zencart to auto populate the product array of products marked as instock only?

I found this function below that is used with country and manufacturers and want to know what needs to be enclosed in the parentheses to array the products.

Code:
zen_draw_pull_down_menu