Gauss/full pivoting problem help

Hey all--

I'm working on a hmwk assignment where we use complete pivoting and Cramer's rule to solve for a vector of unknowns, starting with a square matrix A and solution vector b. I'm then supposed to compare it to Matlabs built-in left-divide function (A\b). My results are not close enough to the Matlab solution so I know I must have something wrong in my code. However I'm not sure where the error is, but I think its in my first "for" loop.

any pointers would be appreciated

here is the code for the main program -- the cramers rule function was given to us and so I know it works. I've pasted the cramers rule code just in case anyone wants to run it. thanks!!!

clc
clear

%define A b and x_ord

A=[8 -2 -1  0 0;
  -2  9 -4 -1 0;
  -1 -3  7 -1 -2;
   0 -4 -2 12 -5;
   0  0 -7 -3 15];

b=[5 2 1 1 5]';

sln=A\b;

x_ord=[1:length(b)]';

%define augmented matrix C
C=A;
C(:,end+1)=b;

[nrC,ncC]=size(C);

for i=1:nrC
pivotval=max(max(abs(C(i:nrC,i:nrC))));

[m,n] = find(abs(C(i:nrC,i:nrC)) == pivotval);

p=m+(i-1); %adjusted row position wrt C
q=n+(i-1); %adjusted column position wrt C

%swapping rows
oldrow=C(i,i:ncC);
C(i,i:ncC)=C(p,i:ncC);
C(p,i:ncC)=oldrow;

%swapping columns
oldcol=C(i:nrC,i);
C(i:nrC,i)=C(i:nrC,q);
C(i:nrC,q)=oldcol;

%swap x ord
oldord=x_ord(i);
x_ord(i)=x_ord(q);
x_ord(q)=oldord;

end

CA=C(1:nrC,1:(end-1));
Cb=C(1:nrC,end);

Cx=Cramers_rule(CA,Cb);

r=length(Cx);

fprintf('Original Order       Shifter Order\nLeft Division        Cramers Rule\n')
fprintf('************************************\n')
for i=1:r
    fprintf(' x(%d) = %.3f    |    x(%d) = %.3f\n',i,sln(i),i,Cx(i))
end
fprintf('************************************\n')

%Cramers Rule function program

function x = Cramers_rule(A,b)

[nra,nca]=size(A);

DA=det(A);

for i =1:nra

C= A;
C(:,i)=b;

x(i)=det(C)/DA;
end