Creating a function which creates a subplot

I want to create a function that will create a subplot, in the subplot the first box will be the orignal image, the second box will be the red dimension of the image or the first matrix, the third green, and last one blue. I am getting 4 empty boxes when I run it also when I put in

Display_RGB_subplots(a,1,cow,cat,dog,doggie)
Undefined function or variable 'cow'.
it gives me that error but when I do

   Display_RGB_subplots(a,1,2,3,4,5)

ans =

      0.0017
I get that. 
Anyways here is my function

function[y1,y2,y3,y4] = Display_RGB_subplots(pic, figurenum, title_1, title_2, title_3, title_4);
y1 = image(pic);
y2 = image(pic(:,:,1));
y3 = image(pic(:,:,2));
y4 = image(pic(:,:,3));

subplot(2,2,1);
plot(y1);
title(title_1)

subplot(2,2,2);
plot(y2);
title(title_2)

subplot(2,2,3)
plot(y3);
title(title_3)

subplot(2,2,4)
plot(y4);
title(title_4)

figure(figurenum)

[Jhangir]

Image analyst where are you brah

[Image Analyst]

I was creating a super nice demo for you.

Answer 1

[Image Analyst]

See my attached demo that does this.