how to give title of the legends?

i have the folowing code that generate step responce of every transfer function in plot i want to give the name of each legend ho i can do

clc
clear all
%muhammad sulaman
%19-ee-65
s=tf('s')
wn=0.7;
k=1;
% z=input('enter the value of zeta::');
z=[0 0.1 0.2 0.5  0.7 0.8 0.9 1]
for ii=1:1:8
    l=z(ii)
    t=linspace(1 ,100,1)
num=k*(wn^2)
den= s^2+2*l*wn*s+wn^2
sys(ii)=num/den

end
stepplot(sys(1),sys(2),sys(3),sys(4),sys(5),sys(6),sys(7),sys(8),t)

[Muhammad]

clc
clear all
%muhammad sulaman
clc
clear all
%muhammad sulaman
%19-ee-65
s=tf('s')
wn=0.7;
k=1;
% z=input('enter the value of zeta::');
z=[0 0.1 0.2 0.5  0.7 0.8 0.9 1]
for ii=1:1:8
    l=z(ii)
    t=linspace(1 ,100,1)
num=k*(wn^2)
den= s^2+2*l*wn*s+wn^2
sys(ii)=num/den

end
stepplot(sys(1),sys(2),sys(3),sys(4),sys(5),sys(6),sys(7),sys(8),t)
legend(sys(1),sys(2),sys(3),sys(4),sys(5),sys(6),sys(7),sys(8),'zeta 0','zeta 00.1','zeta 0.2','zeta 0.5','zeta 0.7''zeta 0.8''zeta 0.9','zeta 1')

its giving the error

Error using legend>process_inputs (line 582)
Invalid argument. Type 'help legend' for more
information.

Error in legend>make_legend (line 340)
[autoupdate,orient,location,position,children,listen,strings,propargs]
= process_inputs(ha,argin); %#ok

Error in legend (line 294)
    make_legend(ha,args(arg:end),version);

Error in lab2taskno1 (line 19)
legend(sys(1),sys(2),sys(3),sys(4),sys(5),sys(6),sys(7),sys(8),'show') 
>> 

[the cyclist]

clc
clear all
%muhammad sulaman
clc
clear all
%muhammad sulaman
%19-ee-65
s=tf('s');
wn=0.7;
k=1;
% z=input('enter the value of zeta::');
z=[0 0.1 0.2 0.5  0.7 0.8 0.9 1];
for ii=1:1:8
    l=z(ii);
    t=linspace(1 ,100,1);
num=k*(wn^2);
den= s^2+2*l*wn*s+wn^2;
sys(ii)=num/den;

end
stepplot(sys(1),sys(2),sys(3),sys(4),sys(5),sys(6),sys(7),sys(8),t)
legend({'zeta 0','zeta 00.1','zeta 0.2','zeta 0.5','zeta 0.7','zeta 0.8','zeta 0.9','zeta 1'})

Answer 1

[the cyclist]

You can use the legend function.