Its really easy to use, thank you guys for your soft, it was really helpful for me! infix enable me freely write my own comments to the PDF document and share the comments with others. It also provides a very convenient way for me to add contents or change the text or add text in any font you like, especially in filling out electronic forms, correct spelling errors, delete words completely and so on. I can save, move, copy, paste and print the comments and contents.thank you