need help with secant method

Below is the script I m trying to run. Instead of getting all roots, I keep getting only one root. I want it to display all roots positive and negative. Can someone help me here?

clc
clear;
disp('Secant Method');
disp('—————-');
y1=input('Enter the depth 1:');
q=input('Enter the flowrate :'); 
z=input('Enter the size of the step :');
E1=y1+(q^2/(2*32.2*y1^2));
E2=E1-z;

x1=input('Initial value of x1=');
x2=input('Initial value of x2=');
tol=input('Tolerance for error=');
f1=x1-E2+q^2/(2*32.2*x1^2);
f2=x2-E2+q^2/(2*32.2*x2^2);
e=1;
ite=0;
while e>=tol;
x3=x2-(f2*(x2-x1)/(f2-f1));
f3=x3-E2+q^2/(2*32.2*x3^2);
e=abs(f3);
ite=ite+1;
if abs(f1)>=abs(f2);
x1=x2;
x2=x3;
f1=f2;
f2=f3;
else x2=x3;
f2=f3;
end
end
disp('The result is');
disp(['f(x)=0 at x3= ', num2str(x3)]);
disp(['f(x)=0 at x2= ', num2str(x2)]);
disp(['f(x)=0 at x1= ', num2str(x1)]);
disp(['Actual tolerance for error= ', num2str(e)]);
disp(['Iteration number= ', num2str(ite)]);