How to exit a loop if file not found

Hi. I'm trying to read several images from a folder. However, the image names are not continuous. For example image 2 is followed by image 4 followed by image 12. I can not change the names of the images. I want the program to exit the loop once an image is not found (if image 3 is not found, it starts the next iteration and reads image 4). How do i do that? This is my code.

    clear all;
      for AT = 1:4

            fdir=fullfile('D:\Documents\Research\MAM LUBNA\Images\BRATS-1 JPG'); 
    filename=sprintf('BRATS_HG000%d_T2.jpg',AT);
    I1 = imread(fullfile(fdir,filename));
        Im{AT} = I1(:,:,1);                % im1=rgb2gray(c1);
GLCM{AT} = graycomatrix(Im{AT},'Offset',[2 0;0 2]);
end

Answer 1

[Thorsten]

Use "exist" to check if the file exists:

 fdir=fullfile('D:\Documents\Research\MAM LUBNA\Images\BRATS-1 JPG'); 
 for AT = 1:4
   filename=fullfile(fdir,sprintf('BRATS_HG000%d_T2.jpg',AT));
   if exist(filename, 'file')
     I1 = imread(filename));
     Im{AT} = I1(:,:,1);                % im1=rgb2gray(c1);
     GLCM{AT} = graycomatrix(Im{AT},'Offset',[2 0;0 2]);
   end
 end

[farheen asdf]

I tried using the code below but then it always skips the commands below.

 if exist(filename) == 0
  continue;
end