thanks anespil, i read it from a book and it says that it is the same meaning, thanks for your correction, by the way can i add you on skype? here's mine: nenjotsu muchas gracías

Hi Nenjotsu. The two expressions have a different meaning. - "Vd. es Isabel, no?" You say this if you are almost sure that the woman is called "Isabel" but you want to be sure. - ¿Es Vd. Isabel? You say this if you are in a place looking for a woman called Isabel and you think she may be her. Anyway, the most common and polite question is "¿Es Vd. Isabel?" and it can be used in the two situations above. Best regards