How to use matlab to observe effect of damping factor(zeta) on response in real time(live)??

I want to use matlab for observing real time effect of changing zeta(damping factor) on system response??

Here is a code of m-file that plots three responses(underdamped,overdamped and critically damped) . This code shows at output three response one underdamped 2nd critically damped and over damped. But i want to do something different in the sense allows me to change value of zeta directly and according to that zeta value response changes,rather than writing new or changing original transfer function

clc
clear all
close all
num1=[16]
den1=[1 4 16]
num2=[16]
den2=[1 8 16]
num3=[16]
den3=[1 10 16]
sys1=tf(num1,den1)