When the form class have constructor method, we can't access its public members from the orther form class. Otherwise we can do it.
   The other problem is: If the form which haven't constructor method, and it's public members can be accessed from others, is not a startup form ---> when execute, it don't run correctly (can't get data passed from other form). But when it is a start up form it run correctly.
   Please help me to explain these things. Thank you so much.