crowding requires more input arguments to run? what does it mean ? i am new to matlab?

this is the code which i am trying to run but it is showing me error .

function newpop=crowding(pop, sizepop, stringlength, a, b, fun, option)
%%%Description: crowding selection methods

if option==1 || option==4
    newpop=pop;
    for i=1:ceil(sizepop/2)
        p1= newpop(i,:);
        p2= newpop(i+1,:);
        [c1, c2]=crossover(p1, p2, a, b, option, fun, stringlength, 1);
        c11=mutation(c1, a, b, fun, option, stringlength, 1);
        c22=mutation(c2, a, b, fun, option, stringlength, 1);
        if abs(p1(:, stringlength+1)-c11(:, stringlength+1))+abs(p2(:, stringlength+1)-c22(:, stringlength+1))...
            <= abs(p1(:, stringlength+1)-c22(:, stringlength+1))+ abs(p2(:, stringlength+1)-c11(:, stringlength+1))
            if fun(c11(:, stringlength+1))>fun(p1(:, stringlength+1))
                newpop(i,:)=c11;
            end
            if fun(c22(:, stringlength+1))> fun(p2(:, stringlength+1))
                newpop(i+1,:)=c22;
            end
        else
            if fun(c22(:, stringlength+1))> fun(p1(:, stringlength+1))
                newpop(i,:)=c22;
            end
            if fun(c11(:, stringlength+1))> fun(p2(:, stringlength+1))
                newpop(i+1,:)=c11;
            end
        end
    end
else
    newpop=pop;
    for i=1:ceil(sizepop/2)
        p1= newpop(i,:);
        p2= newpop(i+1,:);
        [c1, c2]=crossover(p1, p2, a, b, option, fun, stringlength, 1);
        c11=mutation(c1, a, b, fun, option, stringlength, 1);
        c22=mutation(c2, a, b, fun, option, stringlength, 1);
        if norm(p1(:, 2*stringlength+1:2*stringlength+2)-c11(:, 2*stringlength+1:2*stringlength+2))+...
                norm(p2(:,  2*stringlength+1:2*stringlength+2)-c22(:,  2*stringlength+1:2*stringlength+2))...
            <= norm(p1(:, 2*stringlength+1:2*stringlength+2)-c22(:, 2*stringlength+1:2*stringlength+2))+...
            norm(p2(:, 2*stringlength+1:2*stringlength+2)-c11(:,  2*stringlength+1:2*stringlength+2))
            if fun(c11(:, 2*stringlength+1),c11(:, 2*stringlength+2))>fun(p1(:, 2*stringlength+1),p1(:, 2*stringlength+2))
                newpop(i,:)=c11;
            end
            if fun(c22(:, 2*stringlength+1),c22(:, 2*stringlength+2))> fun(p2(:, 2*stringlength+1),p2(:, 2*stringlength+2))
                newpop(i+1,:)=c22;
            end
        else
            if fun(c22(:, 2*stringlength+1),c22(:, 2*stringlength+2))> fun(p1(:, 2*stringlength+1),p1(:, 2*stringlength+2))
                newpop(i,:)=c22;
            end
            if fun(c11(:, 2*stringlength+1),c11(:, 2*stringlength+2))> fun(p2(:, 2*stringlength+1),p2(:, 2*stringlength+2))
                newpop(i+1,:)=c11;
            end
        end
    end
end

%%%%%%%%%%%%%%%%%%%
%End of function
%%%%%%%%%%%%%%%%%%%

[Geoff Hayes]

monika - how are you calling this function and what is the complete error message? Given what you have said in your question, it sounds like you are not passing enough input parameters into the crowding function. Please show us the line of code that you are using to call this function and describe each input.