Flash AS2 - load text dynamically

G'day. I have made some websites using AS2. Is there a timeline on how long AS2 is going to be around? (I notice AS1 is still out there - so am assuming AS2 will not become 'extinct').???
ALSO: I use AS2 to load text into a dynamic text box (not on press or onclick - but soon as the page opens, automatically). It is a text file (.txt) and easy for clients to edit their sites this way. Could some one show me some code on how I could do this same task with AS3??
Thanks kindly in advance!
:)