Bingo!!! Thanks Irvine!!! Anyway, still no regret for buying the 28-300. Only problem is it is not as magical as he claims to be and without IF, I must really put in effort to wipe of the dust after extending the lens to prevent dust from going into it.
no problem man lol.
btw, dust will always find a way to enter into the lens. even my af-d 80-200 two-touch where focusing and zooming r totally internal also got slight dust on the inner elements.