problem with rgb to gray conversion

I got the rgb image output but after doing rgb to gray conversion i got null output image. I attached the image for reference. Suggest the way forward.

[Walter Roberson]

Did you only do rgb2gray() or did you also do im2double() or perhaps double(), or did you possibly copy the contents of the grayscale image into another array?

[SHOBA MOHAN]

I did rgb2gray(). The error was with the code prior to the rgb2gray(), corrected it and got the output also attached the same here. Thanks @ Walter.

[Image Analyst]

So, it's solved now, right?

[SHOBA MOHAN]

Yes @ Image Analyst