st: plot 3 normal distribution on one graph

[yannan shen <yannan2010@gmail.com>]

Dear statalist,
I need to plot three normal distributions on one graph, I want them to
be over each other, not side by side.
The three distributions are:
y1~norm(1, 2)
y2~norm (3, 4)
y3 is a weighted average of y1 and y2, let's say  y3=.5*y1+.5*y2

I found the following code from previous statalist discussion that
looks very helpful:

/* Plot two normal distributions */
#delimit ;
graph twoway (function y=normalden(x,1,2), range(-10 20) lw(medthick))
             (function y=normalden(x,5,3), range(-10 20) lw(medthick)),
title("Normal-Distribution comparison")
xtitle("Normal", size(medlarge)) ytitle("")
xlabel(-10(2)20)
xscale(lw(medthick)) yscale(lw(medthick))
legend(off)
graphregion(fcolor(white));
#delimit cr
/* Stata code ends */

However, I copied and pasted the exact code into stata command window
and the first line returns an error message "Unknown #command"

Why??? I googled the error message but was not able to find a
solution. I cleared the program history, closed and reopned stata, and
tried on different computers, but was unable to find spot the problem.
Can someone please help me? I am using stata IC 12.0

Thank you very much!
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