I work in a native file, SAVE AS a PDF. 

I have searched the Knowledgebase, but am not asking the key words, apparently.

I do NOT want AI to replace the Native file with the PDF on my SCREEN, so I can keep working. ( I am working on quick style changes in the document, making 4-5 versions, and I forgot to manually close out the pdf and get back to the native file-grrrr). 

I know I an turn that feature off somewhere in the Preferences of other programs, but I can't find it in AI, and am in need of what one would call that command. 

Thanks! 

Very much appreciated.

Linda