can i use 2 push buttons to start and stop this code of mine?

i tried using 2 push buttons to start and stop my video processing. But the GUI disappears as soon as i click start. whats seems to be the problem? here is the executable part of my code

 clc;
    close all;
    clear all;

    source = videoinput('winvideo');
    set(source, 'ReturnedColorSpace', 'RGB');
    set(source, 'FramesPerTrigger', 1);
    set(source, 'TriggerRepeat', 50);
    triggerconfig(source, 'manual');
    start(source);
    thresh = 15/255;
    pause(2);
    trigger(source);
    bg = getdata(source,1,'double');
    bg_bw = rgb2gray(bg);

    fr_size = size(bg);
    width = fr_size(2);
    height = fr_size(1);
    f = zeros(height, width);

    for i=1:50

    trigger(source);

    fr=getdata(source,1,'double');
    fr1=fr(:,:,:,1);
    fr_bw1=rgb2gray(fr1);

    bg_fr_diff = abs((double(bg_bw)) - (double(fr_bw1)));

        for j=1:width % if fr_diff > thresh pixel in foreground
            for k=1:height
                if (bg_fr_diff(k,j) > thresh)
                    f(k,j) =255;
                else
                    f(k,j) = 0;
                end
            end
        end
        figure(1),subplot(2,1,1),imshow(fr1)

        subplot(2,1,2),imshow(uint8(f))
        bg_bw=fr_bw1

Answer 1

[Walter Roberson]

Get rid of the "clear all" and "close all".

[Jan]

+1. Another example for the negative effects of the excessively used brute clearing header. Who does beginners tell to extinguish all existing values before running some code?

[Jan]

I've accepted this answer. It would be better, if the OP cares about selecting an accepted answer or at least reply, if this solves the problem already.