I have a question about marriage status is online in Europe?
if u move to another Europe country and how they will know that the person is married already in Europe or not ?
there isn't such a thing as a central european population register so far. So every national authority has to investigate whether your family status does comply with the requirements of marriage. As an example see tinyurl.com/mp3evze (German language).
If you want to learn more about national rules on marriage in Europe, see this informations given by the EU: tinyurl.com/88fbumo