I need code for discretize a tf with "Integral forward"

I did this function and work fine...

function [sys] = adelante(sys, T)

z = tf('z');
T = input('Tiempo de Muestreo: ');
s = (T*z)/(z-1);
FuncT = input('Ingrese la funcion de transferencia: ');

sys = FuncT;

end

but when I do this doesn't works

close all
clear all
clc

syms s

Gs =  (303*s + 463.9)/(s^2 + 508.7*s + 779.9);
Ep = double(limit((1/(1+Gs)),s,0))
T = 0.001;
adelante(Gs,T)

and the function

function [sysd] = adelante(sys,T)

z = tf('z',T)
s = (T*z)/(z-1)

sysd = FuncT;

end

[Walter Roberson]

"this doesn't work" is not enough information for us to go on.