export book 
format any : The export format, specified as an enumeration value or as an extension that appears in the Save as type or Format menu in the Export dialog. Can accept: tagged text/PDF type/EPS type/RTF/text type/XML/JPG/interactive PDF/packaged XFL/SWF/InDesign snip... 
[to alias or text] : The file to which to export the book. 
[showing options boolean] : Used to specify if the PDF Export Options Dialog needs to be shown or not. Can accept: boolean (Default: FALSE). 
[using PDF export preset] : Used to specify the presets for the export which can be the object of the preset type, enumeration for existing presets or user defined presets, or a string naming the preset to be used, but in case Showing Options is true, the preset specified in the ... 
[which documents book content] : Used to specify a list of book content references, from the current book, where the list may contain duplicate entries and if the list is not specified then the entire book contents shall be exported 
[version comments text] : The comment for this version. 
[force save boolean] : If true, forcibly saves a version. Can accept: boolean (Default: FALSE). 

export books format PDF type to pFile using myDPreset ... 

var these_docs = get_docs(); 
app.activeBook.exportFile( ExportFormat.PDF_TYPE, File("~/Desktop/buch.pdf"), true, undefined, these_docs); 
 
function get_docs() { 
	var book_doc_names = app.activeBook.bookContents.everyItem().name; 
 
	var a_dialog = app.dialogs.add({name:"Buchdateien"}); 
	var book_doc_cbs = new Array(); 
	with (a_dialog) { 
		var dc = dialogColumns.add(); 
			for (var n = 0; n < book_doc_names.length; n++) { 
				book_doc_cbs.push( dc.checkboxControls.add({staticLabel: book_doc_names[n], checkedState: true}) ); 
			} 
		} 
	 
	if (a_dialog.show() == false) { 
		a_dialog.destroy(); 
		return undefined; 
	} else { 
		var book_docs = new Array(); 
		for (var n = 0; n < book_doc_names.length; n++) { 
			if (book_doc_cbs[n].checkedState == true) book_docs.push( app.activeBook.bookContents.item( n ) ); 
		} 
		return book_docs; 
	} 
} 

	export active book format PDF type to file_on_desktop version comments "hallo" with showing options without force save which documents these_docs 

tell application "Adobe InDesign CS3" 
	 
	set theFiles to full name of every book content of active book 
	set theList to choose from list theFiles with multiple selections allowed 
	 
	set counter to 0 
	repeat with i from 1 to count of theList 
		set counter to counter + 1 
		set theFile to item i of theList 
		open theFile 
		tell active document 
			export format PDF type to alias (((path to desktop as text) & "Test" & counter as text) & ".pdf") 
		end tell 
	end repeat 
end tell 

tell application "Adobe InDesign CS3" 
	 
	set theFiles to object reference of every book content of active book 
	 
	export active book format PDF type to file ((path to desktop as text) & "Testpdf") version comments "hallo" with showing options and theFiles without force save 
end tell 

export active book format PDF type to file ((path to desktop as text) & "Test2pdf") with theFiles