Graph widgets

Hello to all

At last I found the component to make 2D lines graph in GTK# but I can not compile it.
I downloaded the sources from
www.medsphere.org/projects/widgets

I unpacked the file but when launching the configure script I receive a message saying that I did not MONO.
The problem is that I have Mono and Mono develop installed .
I'm using a UBUBTU 8.04
How to solve?

Thanks to all.

PS
Medsphere.Widgets currently includes 4 widgets:

CPaned:     A helper class for dealing with Gtk.VPaneds with a Gtk.Expander child
FBox:         A "flowed" container for wrapping widgets
GridView:    An Excel-like grid
Graph:        A Cairo-based 2D graph
IconLayout: A Cairo-based icon view