That is for the PDF itself.
What about individual Text Box's that are added in?
Got it. Those are annotations, so look at the annotation properties: http://livedocs.adobe.com/acrobat_sdk/9.1/Acrobat9_1_HTMLHelp/JS_API_AcroJS.88.21.html
You may want to look at the doc.getAnnots documentation for some sample code: http://livedocs.adobe.com/acrobat_sdk/9.1/Acrobat9_1_HTMLHelp/JS_API_AcroJS.88.470.html
That looks like it!