The hostPseudoModel object is the root
object of the host model. Use the host properties and methods at
run time.
Examples of hosts include Acrobat and XFAPresentationAgent (server).
Some hosts may not support all properties and methods. For example,
XFAPresentationAgent does not support xfa.host.messageBox.
Displays a dialog box containing a question
and an entry field for the user to reply to the question. The return
value is a string containing the user's response. If the user presses
the cancel button on the dialog box, the response is null.