I was write the code. i.e.

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Imports System.IO
Imports System.Windows.Forms
Imports System.Drawing




Public Class FrmRollTwellveDice
    Inherits System.Windows.Forms.Form

    'button for rolling dice
    Friend WithEvents cmdRoll As System.Windows.Forms.Button

    'Labels to display die images
    Friend WithEvents lblDie1 As System.Windows.Forms.Label
    Friend WithEvents lblDie2 As System.Windows.Forms.Label
    Friend WithEvents lblDie3 As System.Windows.Forms.Label
    Friend WithEvents lblDie4 As System.Windows.Forms.Label
    Friend WithEvents lblDie5 As System.Windows.Forms.Label
    Friend WithEvents lblDie6 As System.Windows.Forms.Label
    Friend WithEvents lblDie7 As System.Windows.Forms.Label
    Friend WithEvents lblDie8 As System.Windows.Forms.Label
    Friend WithEvents lblDie9 As System.Windows.Forms.Label
    Friend WithEvents lblDie10 As System.Windows.Forms.Label
    Friend WithEvents lblDie11 As System.Windows.Forms.Label
    Friend WithEvents lblDie12 As System.Windows.Forms.Label

    'display roll frequencies
    Friend WithEvents displayTextBox As _
    System.Windows.Forms.TextBox

    'Visual Studio .NET generated code

    'declarations
    Dim randomObject As Random = New Random
    Dim ones, twos, threes, fours, fives, sixes As Integer

    Private Sub cmdRoll_Click _
        (ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles cmdRoll.Click

        'assign random faces to 12 dice using DisplayDice
        DisplayDie(lblDie1)
        DisplayDie(lblDie2)
        DisplayDie(lblDie3)
        DisplayDie(lblDie4)
        DisplayDie(lblDie5)
        DisplayDie(lblDie6)
        DisplayDie(lblDie7)
        DisplayDie(lblDie8)
        DisplayDie(lblDie9)
        DisplayDie(lblDie10)
        DisplayDie(lblDie11)
        DisplayDie(lblDie12)

        Dim total As Integer = ones + twos + threes + fours + fives + sixes

        Dim output As String

        'display frequencies of faces
        output = "Face" & vbTab & vbTab & "Frequency" & vbTab & "percent"

        output &= vbCrLf & "1" & vbTab & vbTab & ones & _
        vbTab & vbTab & String.Format("{0:P}", ones / total)

        output &= vbCrLf & "2" & vbTab & vbTab & twos & _
        vbTab & vbTab & String.Format("{0:P}", twos / total)

        output &= vbCrLf & "3" & vbTab & vbTab & threes & _
        vbTab & vbTab & String.Format("{0:P}", threes / total)

        output &= vbCrLf & "4" & vbTab & vbTab & fours & _
        vbTab & vbTab & String.Format("{0:P}", fours / total)

        output &= vbCrLf & "5" & vbTab & vbTab & fives & _
        vbTab & vbTab & String.Format("{0:P}", fives / total)

        output &= vbCrLf & "6" & vbTab & vbTab & sixes & _
        vbTab & vbTab & String.Format("{0:P}", sixes / total) & vbCrLf

        displayTextBox.Text = output
    End Sub 'cmdRoll_Click

    'displlay a single die image
    Sub DisplayDie(ByVal dieLabel As Label)
        Dim face As Integer = randomObject.Next(1, 7)

        dieLabel.Image = _
        Image.FromFile(Directory.GetCurrentDirectory & _
        "\Images\die" & face & ".png")

        'maintain count of die faces
        Select Case face

            Case 1
                ones += 1

            Case 2
                twos += 1

            Case 3
                threes += 1

            Case 4
                fours += 1

            Case 5
                fives += 1

            Case 6
                sixes += 1

        End Select

    End Sub 'DisplayDie

End Class

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Now the problem is that when I run this code it shows the error which is

'Sub Main' was not found in '_6RollTwelveDice16.Module1'.

Please anybody solve my problem.

Have you created a 'Console Application'?

You should create a 'Windows application'!