imshow() error

[Dincy Paul]

I have some problem with imshow() function in octave 3.2

my code is

clc;

clear all;

img=imread('lennabinary.png');

imshow(img);

 it generate an error:

error: invalid use of script in index _expression_

error: called from:

error: /usr/share/octave/3.2.3/m/image/imshow.m at line 166, column 9

error: /home/keltron/image.m at line 5, column 1