To use a public variable that is inside a class (a form is a class) you have to specify the instance that you are using.
For example:
Dim frmForm1 as New Form1
Dim frmForm2 as New Form2
You can then say Msgbox frmForm1.Variable
Unlike VB6 which creates you a form automatically the first time you call it, you have to explicitly create them.
Use this code for your loop
visual basic code:--------------------------------------------------------------------------------
Dim ctrl As Control
For Each ctrl In Me.Controls
ctrl.Enabled = False
Next
--------------------------------------------------------------------------------