Basic Graphics Logic Help

Public Class Form1
    Dim _Pen As Pen
    Dim min As System.Drawing.Point = New Point(521, 211)
    Dim max As System.Drawing.Point = New Point(1261, 1249)
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
   
        If max.X = 0 Then
            Exit Sub
        End If
 
        Dim Img As New Bitmap(max.X, max.Y)
 
        Dim g As Graphics = Graphics.FromImage(Img)
 
        g.Clear(Color.White)
 
  
 
        _Pen = New Pen(Brushes.LightBlue, 5)
        _Pen.DashStyle = DashStyle.Dash
 
        g.DrawLine(_Pen, min.X, min.Y, max.X, max.Y)
 
 
 
        PictureBox1.Image = Img
    End Sub
 
End Class