Private Sub Form1_Paint(ByVal sender As Object, ByVal e As _
     System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        Dim p As New System.Drawing.Pen(System.Drawing.Color.Red, 2)
        Dim r As System.Drawing.Rectangle
        Dim loc As System.Drawing.Point
        Dim size As System.Drawing.Size
        For Each c As System.windows.Forms.Control In Me.Controls
            If TypeOf c Is System.Windows.Forms.TextBox Then
                CType(c, System.Windows.Forms.TextBox).BorderStyle = _
                  Windows.Forms.BorderStyle.None
                loc = New System.Drawing.Point(c.Location.X, c.Location.Y)
                size = New System.Drawing.Size(c.Size.Width, c.Size.Height)
                r = New System.Drawing.Rectangle(loc, size)
                e.Graphics.DrawRectangle(p, r)
            End If
        Next
    End Sub