LSB substitution by verifying pixel values odd or even

for embedding a message b, keep the pixel value odd for bit 0 and even for bit 1. i have developed code in this manner. But output values are not getting as expected. Somebody plz help to figure out the mistake.

             c=round(rand(2,12));
          m=1:2;n=1:12;
       a(m,n)=c(m,n);
    disp(a);
     b=dec2bin(128);
  l=length(b);
for k=1:l
    if b(k)==1
        if mod(c(1,k),2)==1
            c(1,k)=c(1,k);
        else
            c(1,k)=c(1,k)+1;

            if mod(c(1,k),2)==0
                c(1,k)=c(1,k);
            else
                c(1,k)=c(1,k)+1;
            end
        end
    end
end

 disp(c);