how to encryption, if length plaintext more than 16 character in AES 128 bit?

plaintext = get(handles.txtdp, 'String');
guidata(hObject,handles);
% plaintext = input('Type in an input message (16 characters or less):\n','s');
plaintext = zerofill(plaintext);

key = 'Good[41647]';
%key ='Good[4 16 47]';
% key = input('Type in a secret key/password (16 characters or less):\n','s');
key = zerofill(key);

tic;
% Key Schedule
round_keys = key_schedule(double(key));

% Message Encryption
ciphertext = aes_encryption(plaintext,round_keys);
guidata(hObject,handles);
set(handles.cipher,'String',char(ciphertext));

% Message Decryption
plaintext_recov = aes_decryption(ciphertext, round_keys);
toc;