Hogy kell megcsinálni?

Az a baj hogy csináltam egy mozgó négyzetet visual basic-ban és "kimegy" a képernyőről.Ha valaki tudja mit kell csinálni akkor írja bele ebbe a kódba:

Public Class Form1

Dim moveRight As Boolean = False

Dim moveUp As Boolean = False

Dim moveLeft As Boolean = False

Dim moveDown As Boolean = False

Private Sub Form1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown

Select Case e.KeyValue

Case Keys.Right

moveRight = True

Case Keys.Up

moveUp = True

Case Keys.Left

moveLeft = True

Case Keys.Down

moveDown = True

End Select

End Sub

Private Sub Form1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyUp

Select Case e.KeyValue

Case Keys.Right

moveRight = False

Case Keys.Up

moveUp = False

Case Keys.Left

moveLeft = False

Case Keys.Down

moveDown = False

End Select

End Sub

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick

If moveRight = True Then

boy.Left = boy.Left + 5

End If

If moveLeft = True Then

boy.Left = boy.Left - 5

End If

If moveUp = True Then

boy.Top = boy.Top - 5

End If

If moveDown = True Then

boy.Top = boy.Top + 5

End If

End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Timer1.Start()

End Sub

End Class