Pro LogoPlot, x, y

   ; Return to main level if error occurs.

On_Error, 1 

np = N_Params() ; No. of positional parameters

CASE np OF

   0: Message, 'At least one argument is required in LOGOPLOT'

   1: BEGIN ; Switch dependent and independent arguments.
      dep = x
      indep = Findgen(N_Elements(x))
      END

   2: BEGIN
      dep = y
      indep = x
      END

ENDCASE

DrawLogo ; Opens window, draws logo 

   ; Put plot in region under logo

!P.Region = [ 0.05, 0.1, 0.95, 0.75] 
Plot, indep, dep, /NoErase

   ; Reset system variable

!P.Region = 0 

END