With a global variable can I save the username to be shown later?

Question

I have a program where when logging in (using a username that is already stored in the access comic) I can save a username to show later in the "main menu" used a label or a textbox. I thought about a global variable, but I don’t know if it’s possible! Or is there some easier way?

Thanks to those who helped!

is here the login code

Private Sub PictureBox4_Click(sender As Object, e As EventArgs) Handles PictureBox4.Click
    If TextBox1.Text = "" Then
        MessageBox.Show("Insira o campo do utilizador", "Login", MessageBoxButtons.OK, MessageBoxIcon.Error)
        TextBox1.Focus()
    ElseIf TextBox2.Text = "" Then
        MessageBox.Show("Insira a sua password para o login", "Login", MessageBoxButtons.OK, MessageBoxIcon.Error)
        TextBox2.Focus()
    Else
        Dim conLogin As New OleDb.OleDbConnection("PROVIDER=Microsoft.ACE.Oledb.12.0; Data Source = E:\PAP\projeto\pap.mdb")
        Dim commLogin As New OleDb.OleDbCommand("SELECT login.password FROM login WHERE nome_util = @username AND password = @password", conLogin)
        Dim usernameParam As New OleDb.OleDbParameter("@username", Me.TextBox1.Text)
        Dim passwordParam As New OleDb.OleDbParameter("@password", Me.TextBox2.Text)

        commLogin.Parameters.Add(usernameParam)
        commLogin.Parameters.Add(passwordParam)
        commLogin.Connection.Open()

        Dim reader As OleDb.OleDbDataReader = commLogin.ExecuteReader()
        If reader.HasRows Then
            If TextBox1.Text = "admin" Then
                MessageBox.Show("Login feito com sucesso", "Agrowine", MessageBoxButtons.OK, MessageBoxIcon.Information)
                principal.Show()
                Me.Hide()
            Else
                principaluti.Show()
                Me.Hide()
            End If
        Else
            MessageBox.Show("Utilizador inválido!", "Agrowine", MessageBoxButtons.OK, MessageBoxIcon.Error)
            TextBox1.Clear()
            TextBox2.Clear()
            TextBox1.Focus()
        End If
        commLogin.Connection.Close()
    End If


End Sub