problem in using grTravSale function

I am facing the difficulty is implementing the TSP problem in the following code

xm=50; 
ym=50; 

n = 5       % number of nodes
% random deployment of nodes in 2-D grid 
for i=1:1:n
node(i).x = round(rand(1,1)*xm);
node(i).y = round(rand(1,1)*ym);
fprintf('Plotting (%d, %d)\n', node(i).x, node(i).y);
    plot(node(i).x,node(i).y,'x');
    text(node(i).x,node(i).y,int2str(i),'FontSize',10);
    grid on;
end 
 % calculating distances between each node with every other node
index = 5;
for l = 1 : index
    for m = 1 : index
          if l ~= m
%               tem(l,m)= tovisit(l), tovisit(m);
            distances(l,m) = round(sqrt((node(l).x - node(m).x)^2 + (node(l).y - node(m).y)^2));
        else
            distances(l,m) = 0;
        end
    end
end
close;

for l = 1 : index
    for m = 1 : index
        fprintf('%d, ', distances(l,m));
    end
    fprintf('\n');
end
index
a = size (distances);

% using grTravSale to compute the sequence to visit
ou(a,b) =grTravSale(distances(index, index));

Upon the execution of code I am facing the following error

??? Error using ==> grTravSale at 40 Must be not less than 3 cities!

Error in ==> temp at 36 ou(a,b) =grTravSale(distances(index, index));

Although the number of nodes are 5, Please help me in this regards. Thank you