while loop isn't working? what's my mistake??HELP

I'm new in MATLAB.. I tried to run the following code, but the loop isn't working :( would you plz explain for me what's happening???

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Mb=390;
Tb=110;
TCini=107.26;
Tv=80
TV=110;
Mpwini=3;
tolMpw=2;
s0=0.45;
Cp_cavg=4.18;
Tc=103.25;
x=0;
tc=TCini-4;
i=0
while tolMpw > 1 
     A = 8.325e-2 + 1.883e-4*TV + 4.02e-6 *TV^2
     B = - 7.625e-4 + 9.02e-5*TV- 5.2e-7*TV^2
     C = 1.522e-4 - 3e-6*TV - 3e-8*TV^2
     delTv=TV-Tv
     NEA    =((33*delTv)^0.33)/TV
     hf= 2501.897149 - 2.407064037* TV + 1.192217e-3*TV^2-1.5863e-5*TV^3
     s=s0+0.001
     BPE = A*s + B*s^2 + C*s^3
     Tv=Tb-NEA-BPE
     Mb=Mb-Mpwini
     Q= Mb*Cp_cavg*(TCini-Tc)
     Mpw=Q/hf
     tolMpw=(Mpw-Mpwini)
     display(i)
     Mpwini=Mpw;
     s0=s;
     i= i+1
end
------------------------------------------------------------------------------

thanks a lot!!!!

[Image Analyst]

The code runs without generating an error. Please explain what "isn't working" means to you.

[B]

Thank you very much :) It's actually working..Sorry for wasting your time (I wasted around 4 hrs, and then after reading your comment, I've added "tolMpw=abs(Mpw-Mpwini)" which is giving the correct results..