用GUI做蒙特卡洛模拟问题

function CSXZ_Callback(hObject, eventdata, handles)
% hObject    handle to CSXZ (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
strcs={'模拟次数:'};
valuecs={'1000'};
cs=inputdlg(strcs,'输入参数',1,valuecs);
M=cs(1,1);
N=str2double(M);

想在

function ZTFB_Callback(hObject, eventdata, handles)
% hObject    handle to ZTFB (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
strzt={'均值:','方差'};
valuezt={'0','1'};
esigma=inputdlg(strzt,'输入参数',1,valuezt);
E=esigma(1,1);
E=str2double(E)
Sigma=esigma(2,1);
Sigma=str2double(Sigma)
        while(j<=N),
            j=j+1;
            Nx=NormD(E,Sigma);
            x(l,j)=Nx;
        end

中调用N的值，报错为

Undefined function or variable 'N'.

Error in ==> D:\MATLAB6p5\work\GUI1.m (ZTFB_Callback)
On line 112  ==>         while(j<=N),

Error in ==> D:\MATLAB6p5\toolbox\matlab\uitools\gui_mainfcn.m
On line 66  ==>         feval(varargin{:});

Error in ==> D:\MATLAB6p5\work\GUI1.m
On line 42  ==>     gui_mainfcn(gui_State, varargin{:});

??? Error while evaluating uimenu Callback.

WORKSPACE里也没有数据

请问如何处理，谢谢了！