how 'error' command work?

[Chaturapadh Nakavachara]

sorry for too many question but would you mind to answer me this question :)
When I use Matlab
this m file
-------begin of win.m-----
a=input()
if(a)
printf('a is not zero or empty');
else
error('a is zero or empty');
end
printf('this line will not show');
-------end of win.m-------
but in octave if i use this file
the line 'this line will not show' will appear
would you mind to give me some suggestion for which commad i should use
instead of error
thanks a lot