Error ? Undefined function or variable 'AppName'. ??? why ? can't find the exact problem ?

 %x(AppName,status,dataOn);
      % xx(AppName,number);
                      xx=[];
                      x={0};
               if Sign == 1
                        if appm==0 
                            x{end+1,1}.AppName=aa1{selA,1}.Type;
                            status='[On]';
                            dataOn=i-7;
                            app=AppName;
                          appm=1;
                        end
                        SignStr = '[On]';
                        iCount = iCount + 1;
                        if ~isempty(r{selA,1})
                            r{selA,1} = r{selA,1} + 1;
                        else
                            r{selA,1} = 1;
                        end
                    else
                        if x{end}.AppName == aa1{selA,1}.Type
                            AppName=aa1{selA,1}.Type;
                            status='[Off]';
                            dataOff=i-7;
                        end
                        SignStr = '[Off]'; 
                        iCount = iCount - 1;
                        if isempty(r{selA,1})
                            r{selA,1} = [];  %%20181006
                            EventLog(Log_Event, FileVersion, datestr(datetime()), datestr(d{end, 1}.Time), 'There is no open event!')
                            disp("There is no open event!");
                        elseif r{selA,1} == 1
                            r{selA,1} = [];
                        else
                            r{selA,1} = r{selA,1} - 1;
                        end
                    end
                 if rem(length(x),2)==0
                        n=x(end-1,1).dataOn;
                        xx{end+1,1}.AppName=x{end,1}.AppName;
                        xx{end+1,1}.number=x{end}.dataOn-d{end-1}.dataOn;
                   fprintf('Switching appliance：%sTurn on and off： %d',xx{end}.AppName,xx{end}.number);
                        if n>=x{end-1}.dataOn && n<=x{end}.dataOn
                            fprintf('Switching appliance：%sactive： %.3freactive： %.3f',x{end}.AppName,d{x{end-1}.dataOn}.P,d{x{end-1}.dataOn}.Q);
                        end
                  end

[madhan ravi]

Duplicate of

https://www.mathworks.com/matlabcentral/answers/435261-undefined-function-or-variable-appname-why