You will not be able to save changes to your forms without purchasing the full version of Adobe Acrobat. If you do not have the full version of Acrobat, and are working with the free download (Adobe Acrobat Reader), be sure to print your forms after completing the fields. YOU CAN NOT SAVE THE FORM TO DISK AND EXPECT THE FIELDS TO STILL BE COMPLETED. YOU MUST PURCHASE THE FULL VERSION OF ADOBE ACROBAT TO TAKE ADVANTAGE OF THIS FUNCTIONALITY.