Dear Mark,

I think that I haven't descript not detail and clear. When I using your PDF coding to product a PDF file and send to customer. Customer can change the document if they have installed the Acrobat 4.0. It is because Acrobat 4.0 can insert or modify the content of PDF file and look at the document info which allow to change docment. In my case, I must make sure that customer cannot change the document due to company policy. If they can change the document content, they can claim the fault and try to break the agreement. Please give me some hints/suggestion, thank you very much .....

Best Regards,

Justy Chow