Как объявить глобальную переменную

Public Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ' Declare CspParmeters and RsaCryptoServiceProvider 
        ' objects with global scope of your Form class.
        Dim cspp As CspParameters = New System.Security.Cryptography.CspParameters
        Dim rsa As RSACryptoServiceProvider
 
        ' Path variables for source, encryption, and
        ' decryption folders. Must end with a backslash.
        Dim EncrFolder As String = "c:\Encrypt\"
        Dim DecrFolder As String = "c:\Decrypt\"
        Dim SrcFolder As String = "c:\docs\"
 
        ' Public key file
        Dim PubKeyFile As String = "c:\encrypt\rsaPublicKey.txt"
 
        ' Key container name for
        ' private/public key value pair.
        Dim keyName As String = "Key01"
    End Sub

Module Module1
    Public ПЕРЕМЕННАЯ As String
End Module

Public Class Form1
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        KNOPKA()
    End Sub
 
    Public Function KNOPKA()
        ' Исполняемый код при нажатие кнопки
    End Function
 
End Class