Viewing PDFs within an application

I am a user of Acrobat 8 Prof. An application with which I am currently using allows for PDF files to viewed within the application. However, when I attempt to view these files a separate Acrobat window is being launched. I believe the setting for this function is within the preferences, but I cannot recall which value should be popluated and/or which flag should be checked to enable this intra-viewing capability.