Sorry for the late response. I've looked at your script. It's not not correct.
Since Customer A all ready made a purchase in may 2013 he cannot be registerd as a new customer in july.
Same goes for customer B who made a purchase in june, he cannot be registerd as a new customer in july.
What I would like to achieve is that I want to display a list of the current new customers per month. So in July when I get new data, I will have new customers for that month and the customers of the previous month are considerd as old.
note: I need to use both tables to achieve the above. The customer table and the date table.
The flag is supposed to help you so that you don't have to create all the possibilities in the script. Enclosed you cand find my earlier example with three listbox objects that I think do what you desire.
Hope it helps.
Ps. Sorry for not replying earlier but in the last weeks I've been very busy.