Using while loop: Unable to obtain value

I'm trying to use a while loop and continue getting the request to input a "bad thickness value, re-enter" from my code. I'm not sure what I'm doing wrong, or if I'm just not accoutning for something.

diameter = 10.2; %the sphere outer diameter
thick = input('enter thickness of sphere');
while (thick <= 0)
thick = input('bad thickness value, re-enter')
end
density = 1.25;
Rout = diameter/2;
Rin = diameter/2 - thick;
Volume = 4/3*pi*(Rout^3-Rin^3);
%mass = density*volume
mass = density*Volume;
%weight = mass*g
g = 9.81;
weight = mass*g;
disp(['The sphere''s weight is= ', num2str(weight)])
enter thickness of sphere -0.2
%the line below is what I don't understand, I thought the while loop took care of it?
bad thickness value, re-enter

Answer 1

[David Hill]

The code is working properly. If you enter a negative number or zero, the code prompts you to reenter a correct value.

[Danny Allen]

Thank you so much for checking it! I was a little confused and after watching a few videos I understand a bit more now! Thank you again.