Boolean? Arrays?

Question

I'm creating a program at school in VB6 that i was just trying to work on at home w/ my .NET program. (its the TicTacToe) I have Dim Xturn As Boolean in General Declarations. Then under my button I have If Xturn = True Then cmdTTT.Text = "X" blah blah but why does it say that "Name 'Xturn' is not declared"? I thought i did declare it. Also, what is the equivalent of using arrays in .NET? Do I have to use variables or something?