I didn't say I couldn't answer your question but it certainly appears that you don't want to answer mine!
I said that as I asked first, I expect an answer first. Then I said I'd answer your question - as my post above explained quite simply. 8)
I don't know why you think it is alright to expect an answer from me before you answer my question! You've got it the wrong way round!!
However, as you are claiming that I "can't" answer your question (which I can actually), perhaps you are thinking that because you "can't" answer mine!!!