The following JavaScript code in the containing HTML content sends a message to the JavaScript in the PDF file:pdfObject = document.getElementById('PDFObj'); pdfObject.postMessage(['testMsg', 'hello']);The PDF file can include JavaScript for receiving this message. You can add JavaScript code to PDF files in a number of contexts, including the document-, folder-, page-, field-, and batch-level contexts. This section discusses only the document-level context, which defines scripts that are evaluated when the PDF document opens.A PDF file can add a messageHandler property to the hostContainer object. The messageHandler property is an object that defines handler functions to respond to messages. For example, the following code defines the function ...