.NET VB.net Maximum won't display

Code
Private Sub Verify(ByRef group, ByVal rating, ByVal names, ByVal telephone)

        Dim counter As Integer

        For counter = 1 To 3

        Do

        names(counter) = InputBox("Please enter your name")

        If names(counter) = "" Then

            MsgBox ("Please enter your name")

        End If

        Loop Until names(counter) <> ""

        Do

        telephone(counter) = InputBox("Please enter your telephone number")

        If telephone(counter) = "" Then

            MsgBox ("Please enter your telephone number")

        End If

        Loop Until telephone(counter) <> ""

        Do

        group(counter) = InputBox("Please enter your group size (0-20)")

        If group(counter) > 20 Then

            MsgBox ("Please enter a group size between 0 and 20")

        End If

        Loop Until group(counter) < 20

        Do

        rating(counter) = InputBox("Please enter your group rating (0-10)")

        If rating(counter) > 10 Then

            MsgBox ("Please enter a rating between 0 and 10")

        End If

        Loop Until rating(counter) < 10

        Next counter

        Call max(maximum, group)

        Call Display(group, rating, names, telephone)

        End Sub

    

    Private Sub max(ByRef maximum, ByRef group)

        maximum = 0

        For counter = 1 To 3

        If group(counter) > maximum Then

        maximum = group(counter)

        End If

        Next counter

    End Sub

     

    Private Sub Display(ByVal group, ByVal rating, ByVal names, ByVal telephone)

        For counter = 1 To 3

        PictureDisplay.Print ("Name: " & names(counter))

        PictureDisplay.Print ("Telephone Number: " & telephone(counter))

        PictureDisplay.Print ("Group Size: " & group(counter))

        PictureDisplay.Print ("Group Rating: " & rating(counter))

        Next counter

        PictureDisplay.Print ("Maximum group size: " & maximum)

        Call ask

    End Sub