Order Id Problem

in my cscart website the order id format looks like #20150216-00011

the problem we met recently is that when order id is #20150216-09999

next order id becomes #20150216-00000

I expect that the next order id should be #20150216-10000, rather than #20150216-00000.

How to fix it? is it configuration somewhere or coding somewhere?

Good day peter_xr,

As I understood you are using some kind of custom modification. Is that correct?

Please hire someone to examine the modification made by 3rd party as the described feature is not a part of default CS-Cart installation. We can help you with this examination

Yes, I had developer customise it before. Thank you all.