index out of bound in matlab : picking up similar matching points in 2 matlab images

i am doing a program, in which i have 2 images and i have to find matches in them. now when i run this code, it shows the point match but is showing an error. due to this error, my code cannot proceed further to the next part of the code.

my code is

%%Read in two images 
  imgl = imread('pic410.bmp');
  imgr = imread('pic430.bmp');

    %%display image pair side by side
    [ROWS, COLS, CHANNELS] = size(imgl);
    disimg = [imgl imgr];
    image(disimg);

    % You can change these two numbers, 
    % but use the variables; I will use them
    % to load my data to test your algorithms
    % Total Number of control points

    Nc = 15;
    % Total Number of test points
    Nt = 4;

    %%After several runs, you may want to save the point matches 
    %%in files (see below and then load them here, instead of 
    %%clicking many point matches every time you run the program

     load pl.mat pl;
     %load pr.mat pr;

    %%interface for picking up both the control points and 
    %%the test points

    cnt = 1;
    hold;

    while(cnt <= Nc+Nt)

    %%size of the rectangle to indicate point locations
    dR = 50;
    dC = 50;

    %%pick up a point in the left image and display it with a rectangle....
    %%%if you loaded the point matches, comment the point picking up (3 lines)%%%
    %[X, Y] = ginput(1);
    %Cl = X(1); Rl = Y(1);
    %pl(cnt,:) = [Cl Rl 1];
    %CANNOT COMMENT THIS BELOW 2-3 LINES 
    %%and draw it 
    Cl= pl(cnt,1);  Rl=pl(cnt,2); 
    rectangle('Curvature', [0 0], 'Position', [Cl Rl dC dR]);

    %%and then pick up the correspondence in the right image
    %%%if you loaded the point matches, comment the point picking up (three lines)%%%

    %[X, Y] = ginput(1);
    %Cr = X(1); Rr = Y(1);
    %pr(cnt,:) = [Cr-COLS Rr 1];
    %CANOT COMMENT THESE BELOW 2-3 LINES 
    %%draw it
    Cr=pr(cnt,1)+COLS; Rr=pr(cnt,2);
    rectangle('Curvature', [0 0], 'Position', [Cr Rr dC dR]);
    plot(Cr+COLS,Rr,'r*');
    drawnow;

    cnt = cnt+1;
    end

the error is

Attempted to access pl(12,1); index out of bounds because size(pl)=[11,3].

Error in FmatGUI_2 (line 45)
Cl= pl(cnt,1);  Rl=pl(cnt,2);

if i disable these lines, then i cannot see the image. so i have to keep these lines without the error. please let me know how to solve this problem.