please review the code for randomization test

Hi.

I created code for Randomization t-test (2-samples)

The final p value appears as 1 for all row data.

Please review the code below and the attached data for correctness.

The data I used is attached to Excel.

Thank you.

[code]

eA= y- yhatA; 
eB= y- yhatB; 
diff=eA.^2-eB.^2; 
meandiff=mean(diff); 
n=length(diff); 
niter = 199 
sum= 0; 
for k = 1: niter 
     randomsign=2*round(rand(1,n))-1; 
     signeddiff =randomsign. *diff; 
     meansigneddiff=mean(signeddiff); 
     sum=sum+... 
     (abs(meansigneddiff)> 
     =abs(meandiff)); 
end 
pvalue=(sum+1)/(niter+1)