Help:Manual PDFjavascript
Enhancing Scribus PDF with JavaScript
Scribus has very complete support for adding interactive features to PDF. Perhaps, no other application can offer more in the area of PDF forms, presentations or other interactive elements than Acrobat Pro itself. This is enabled via dialog boxes in the field properties and by adding JavaScript based functions attached to PDF buttons and text fields. The best way to demonstrate this is via a PDF tutorial which has these features:
The "JavaScripting PDF " from [1] is a step by step guide for beginners to enhance PDF with JavaScript.
Direct Link:
http://docs.scribus.net/content/en/pdfs/javascriptpdf.pdf
After reading this PDF tutorial, the next section, PDF Web Forms walks you through the step by step creation of a web based PDF form with a sample .php snippet to read the submitted data.
This is best viewed by Acrobat Reader 5.x downloaded and run outside of a browser. You can typically right click the links to the PDF and Save As.*. to save the file locally. Other PDF viewers do not have the JavaScript support to view this properly.
Lastly, a good link for with code examples: http://www.accesspdf.com/article.php/20050510131850979 for using the pdftk utilities to allow using html as a front end to filling in PDF forms.