Thread Subject: field and structure calling

Did I misunderstand the use of field and structure?
Can someone point out my mistakes please.


%% PLAY AUDIO
function select_audio_Callback(hObject, eventdata, handles)

handles.randValue = rand;
wavplay(samples{ceil(length(samples)*handles.randValue)}{:}) ;

guidata(hObject, handles);

%%------------------------------

%% ANSWER

function answer_faster_Callback(hObject, eventdata, handles)

%% write answer in text with the corresponded audio
csvwrite(num2str (get(handles.randValue, 'Value')),[1]);

guidata(hObject, handles);