ช่วยดูโค้ด ลูกบอลเด้งหน่อยครับ พอคลิกเม้าส์ที่บอล บอลจะหาย แต่ติดที่ผมหาแกนอีก 2 แกนไม่เป็นครับ แนะนำหน่อย

Public Class Form1
    Private dx As Integer
    Private dy As Integer
    Private x As Integer
    Private y As Integer
    Private ix As Integer
    Private iy As Integer
    Private ballWidth As Integer = 50
    Private ballHeigth As Integer = 50
    Dim g As Graphics = Me.CreateGraphics
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Timer1.Interval = 5
        Dim rnd As New Random
        dx = rnd.Next(1, 4)
        dy = rnd.Next(1, 4)
        x = rnd.Next(0, Me.ClientSize.Width - ballWidth)
        y = rnd.Next(0, Me.ClientSize.Height - ballHeigth)
        Me.SetStyle(ControlStyles.AllPaintingInWmPaint Or ControlStyles.UserPaint Or ControlStyles.DoubleBuffer, True)
        Me.UpdateStyles()
    End Sub
    Private Sub Form1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseClick
        ix = e.X
        iy = e.Y
        If ix >= x And iy >= y Then
            Timer1.Stop()
            g.Clear(Me.BackColor)
        End If
    End Sub
    Private Sub Form1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        e.Graphics.Clear(Me.BackColor)
        e.Graphics.FillEllipse(Brushes.Blue, x, y, ballWidth, ballHeigth)
        e.Graphics.DrawEllipse(Pens.Black, x, y, ballWidth, ballHeigth)
    End Sub
    Private Sub Timer1_Tick_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        x += dx
        If x < 0 Then
            dx = -dx
        ElseIf x + ballWidth > Me.ClientSize.Width Then
            dx = -dx
        End If
        y += dy
        If y < 0 Then
            dy = -dy
        ElseIf y + ballHeigth > Me.ClientSize.Height Then
            dy = -dy
        End If
        Me.Invalidate()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Timer1.Start()
    End Sub
End Class