Stopping my custom slider control in a set postion

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 Public Class UserControl1
 
    Private Sub UserControl1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If Not MoveImage Is Nothing Then
            X1 = (Me.Width / 2) - (MoveImage.Width / 2)
            X2 = (Me.Width / 2) + (MoveImage.Width / 2)
            Y1 = (Me.Height / 2) - (MoveImage.Height / 2)
            Y2 = (Me.Height / 2) + (MoveImage.Height / 2)
            Invalidate()
        End If
    End Sub
    Dim X1, X2, Y1, Y2 As Integer 'For finding out where the Pointer will be relative to the cursor. 
    Dim IsMouseDown As Boolean 'Is the cursor pressed down.
    Private MoveImage As Bitmap
    Public Property PointerImage() As Bitmap
        Get
            Return MoveImage
        End Get
        Set(ByVal value As Bitmap)
            MoveImage = value
        End Set
    End Property
 
    Private Sub UserControl1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
        IsMouseDown = True
    End Sub
 
    Private Sub UserControl1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
        If IsMouseDown = True Then
            If X1 < 300 And X1 > 0 Then
                X1 = e.X - MoveImage.Width / 2
                Invalidate()
            ElseIf X1 > 299 Then
                X1 = e.X - MoveImage.Width / 2
                Invalidate()
            End If
        End If
    End Sub
 
    Private Sub UserControl1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseUp
        IsMouseDown = False
    End Sub
 
    Private Sub UserControl1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        If Not MoveImage Is Nothing Then
            e.Graphics.DrawImage(MoveImage, New PointF(X1, Y1))
        End If
    End Sub
End Class