[alien1]

I'm running 3.2.2 Pro with Affiliate.

I think what I have to do is add a date field to each product. then, add a table called, say, "Availability."

If I add a button "Check availability," then a customer can choose the tour product, then that button calls a subroutine taking the date he entered and check if there is space in the table, deduct the number of spaces he is booking, then carry on with the check-out.

If you are suggesting that the "promotions.tpl" file is where I add the subroutine, you might be correct, I just have not analyzed it that much.