Dim blackPen As New Pen(Color.Black, 3) -- pen not defined ??

i am trying to draw in a picturebox
i have Imports System.Drawing.Graphics at top of form
but in a subroutine i define black pen with
Dim blackPen As New Pen(Color.Black, 3)
compiler says that Pen is not defined.

its got to be something rather simple since all the examples i have searched for use this type of declaration

thanks

follys