\documentclass{article}
\usepackage{docassembly}
\usepackage{lipsum}

\hypersetup{pdfpagemode=UseNone}

% Look in the Adobe Acrobat JavaScript manual under the app.openDoc() to see all the possible parameters.
\begin{docassembly}
% Open supportDoc.pdf, but hide it
var doc=\appopenDoc({
  oDoc:  this,
  cPath: "resources/supportDoc.pdf",
  bHidden: true
});
console.clear(); console.show();
console.println("Opening " + doc.documentFileName);
% Get the field object, for the text field that has title of "Name"
console.println("Getting the field value of \"Name\"");
var f=doc.getField("Name");
% Show the value of that text field and display it in the console
console.println("The value of \"Name\" is "+f.value);
% Close the hidden doc
console.println("Closing " + doc.documentFileName);
doc.closeDoc();
% Save the current document
console.println("Saving the current document " + this.documentFileName);
\executeSave();
\end{docassembly}

\begin{document}

\lipsum[1-30]

\end{document} 