GUI编程完后出现的问题

小孩

编程完回调函数时，在MATLAB的窗口上显示着：
??? Error: File: my_gui2.m Line: 337 Column: 1
Function definition is misplaced or improperly nested.
Error in ==>
@(hObject,eventdata)my_gui2('popupmenu4_CreateFcn',hObject,eventdata,guidata(hObject))

??? Error using ==> struct2handle
Error while evaluating uicontrol CreateFcn
第337行是：
function popupmenu4_CreateFcn(hObject, eventdata, handles)
% hObject    handle to popupmenu4 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called
% Hint: popupmenu controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end
在它之后的函数都不能运行啦~~
红色那行显示的主要是错误信息是：FUNCTION keyword use is invalid here .this might cause later messages about END
不知道该怎么解决，很着急，小女子也是刚接触GUI很短时间，希望有高手帮忙，十分感谢！！！不知道写的清楚不清楚
有问题可以提出来，谢谢啦！！

ChaChing

个人水平专业有限, 总觉得LZ写的不清楚!?
到底错误信息是什么?