PRO fib, char=char
print, 'lets run the fibonacci sequence'
print, 'enter the number at which you wish to stop'
stp=''
read, stp
a=0
b=1
while (b le stp) do begin
if not keyword_set(char) then print, b $
else print, make_array(b,1,value=char)
c=b+a
a=b
b=c
endwhile
end