I would like to know the signature appearance can it control by program code?
when the user sign the signature, can the program in form control what the signature's appearance display?
Can you elaborate the question?
One can use LiveCycle Digital Signature service APIs to add signature field and use various apperance options available with that API.
More info @ http://help.adobe.com/en_US/livecycle/10.0/ProgramLC/javadoc/com/adobe/livecycle/signature s/client/types/PDFSignatureAppearanceOptionSpec.html
Retrieving data ...