Build in a Page Count Limit to previous projects.

Hi Ninad I would like to be able to distribute the software that you worked on in the two previous projects to customers. However we need to sell it with a page compression limit depending on what the client wants...and pays for. This is not too difficult to do.....however....the challenge we have is to be able to give the user and new page count limit after the previous one has been used up and if they wish to purchase another page limit option. How can we reset the page count limit and/or add a new page limit to the software? Currently I can do this by encrypting the [login to view URL] file to execute a certain number of times and it reports back to our License Server to authenticate that they have a license and update our server with the number of executions. So we can see what the customer is doing. This is great...but....if a customer compresses a PDF that has many pages in it (i.e. a multi-page document) then this only counts as one page because the [login to view URL] only executes once to compress the multi-page document. So I am sure you see the problem we have. i.e. the customer could compress 10 PDF documents that each had 100 pages (i.e.1000 pages in total) but the software would only count 10 (i.e. 10 executions of [login to view URL]) So I am sure you see the problem. So we need to think of another way of setting a limit to the page count. My first thoughts/idea is to give the customer a unique code key that they can enter into the software which would add another page limit onto the expired one, However I am sure there are many other ways of doing this and I was hoping you might have some ideas? Of course we have to come up with a solution that the Customer cannot abuse or reset/change themselves. We need to have full control so that the Customer has to come back to us for a new license key to extend and/or reset their license that gives them a new page limit/count. I hope this gets your thinking and is something you would like to work on for us? Let me know if you need any more details or info'. Thanks very much Ninad I appreciate your help with our software.development. Best regards Greg