Matlab ball follower code not working ( suppose to show correct command) for simulation only

clear;
clc
vid=videoinput('winvideo',2');%PLEASE CHECK THE RESOLUTION BEFORE TESTING
set(vid,'FramesPerTrigger',1);
set(vid, 'ReturnedColorspace', 'rgb')
%preview(vid);
pause(10);
rgb_image = getsnapshot(vid);
[a b c]= size(rgb_image);
y=a;
x=b;
x1=x/2-120;
x2=x/2+120;
y1=y/2-30;
y2=y/2+30;
%ser=serial('COM1');
%fopen(ser);
while(1)
    rgb_image = getsnapshot(vid);
    flushdata(vid);
    rbar=0;
    cbar=0;
    e=0;
    fR=rgb_image(:,:,1);fG=rgb_image(:,:,2);fB=rgb_image(:,:,3);
    I = imsubtract(fR(:,:,1), rgb2gray(rgb_image));
   % I=((fR>=80) & (fG<=70) & (fB<=70));%PLEASE SET THE THRESHOLD VALUES BEFORE TESTING
    se=strel('disk',20);
    B=imopen(I,se);
    final=imclose(B,se);
    [L,n]=bwlabel(final);
    imshow(rgb_image);% THIS LINE IS NEEDED ONLY FOR TESTING SIMULATION
    hold on % THIS LINE IS NEEDED ONLY FOR TESTING SIMULATION
    for k=1:n
        [r,c]=find(L==k);
        rbar=mean(r);
        cbar=mean(c);
        plot(cbar,rbar,'Marker','*','MarkerEdgeColor','B','MarkerSize',20)% THIS LINE IS NEEDED ONLY FOR TESTING SIMULATION
        e=(((cbar>=x1)*2*2*2) + ((cbar<=x2)*2*2) + ((rbar>=y1)*2) + (rbar<=y2))
    end
     hold off
     switch (e)
        case 5
            disp('left');
        case 6
            disp('left');
        case 7
            disp('left');
        case 9
            disp('right');
        case 10
            disp('right');
        case 11
            disp('right');
        case 13
            disp('forward');
        case 14
            disp('back');
         otherwise
            disp('stop');
     end
end
%fclose(ser);

    if true
      % code
    end

Answer 1

[Image Analyst]

Usually what most people do when their code is "not working" is to use the debugger . Go here to learn how: http://blogs.mathworks.com/videos/2012/07/03/debugging-in-matlab/ If you do that it will be much faster for you than debugging via the Answers forum where we have to go back and forth multiple times, with long delays in between, asking questions like "What exactly does 'not working' mean?" Once you learn to debug yourself, you can rapidly solve these questions without us.