What you have to doWhat you need is an integer (or better still and Enumerated variable) which determines what state the traffic light sequence has got up to and moves the sequence from one state to the next every time a Command Button is pressed. There are six states as indicated above. It is a requirement of this exercise that only the Properties that absolutely need changing should be updated after each click of the Command Button. and the program listing: Public Class Form1 Dim i As Integer Private Sub BntStart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStart.Click i = i + 1 If i = 1 Then picGreen.Visible = False picAm.Visible = True End If If i = 2 Then picAm.Visible = False picRed.Visible = True End If If i = 3 Then picPel.BackColor = Color.Green End If If i = 4 Then picPel.BackColor = Color.Red End If If i = 5 Then picRed.Visible = False picRedam.Visible = True End If If i = 6 Then picRedam.Visible = False picGreen.Visible = True i = 0 End If End Sub Private Sub btnEnd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEnd.Click End End Sub Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load End SubEnd Class[note: this is a slightly older version i've got a newer one around somewhere where it's commented n stuff.