Graphical Windows

Hello,

Here is my problem.  I am trying to run and learn R trough the 
terminal application of my Mac (it runs on Panther).

So here it goes I just recently installed R, in unix mode (terminal) 
by following the attached web page.  The trouble is when I try to run 
either demo(graphics), demo(image) or even just a plot(x,y) of random 
values, no windows opens.  I get nada...

Could you please give me a hand!

I don't know any one who can give me a hand on this!