GUI Serial Com interrupt

i have a GUI and a state machine to read the data i receive but at the moment it works when i press a button. i want it to work continuously using interrupt how can i do it? i can receive a data of 40 bytes and need to save it through the iterations how can i do it

to be more specific: here is my code.only the relevant part: where i set the serial port and the funcion i try to call when the INTERRUPT occurs

the error i see is:

Error using feval
  Invalid function name '@intcon1'.

    Error in instrcb (line 36)
            feval(val{1}, obj, eventStruct, val{2:end});

    Warning: The BytesAvailableFcn is being disabled. To enable the callback property
    either connect to the hardware with FOPEN or set the BytesAvailableFcn property.
* _THE CODE:_*

function SELECT_COM_BUTTON_Callback(hObject, eventdata, handles)
  %deactivate actual button
  set(hObject,'Enable','off');pause(0.1)
  serPortn = get(handles.port_list, 'Value');
  if serPortn == 1
          errordlg('Select valid COM port');
  else
          serList = get(handles.port_list,'String');       
          com = serList{serPortn};
  end

    contents = get(handles.baud_list,'String');
    vel=str2double(contents{get(handles.baud_list,'Value')});
    % serial port configuration
    handles.SerPIC = serial(com);%choose serail COM
    set(handles.SerPIC,'BaudRate',vel);%speed
    set(handles.SerPIC,'DataBits',8);%8 bits of data
    set(handles.SerPIC,'Parity','none');%no parity bits
    set(handles.SerPIC,'StopBits',1);%one stop bit
    set(handles.SerPIC,'FlowControl','none');%no flow control

    handles.SerPIC.BytesAvailableFcn = {'@intcon1',handles};
    set(handles.SerPIC,'BytesAvailableFcnMode','byte');  
    set(handles.SerPIC,'BytesAvailableFcnCount', 1);  

    fopen(handles.SerPIC);
    %opening message of serial port (user needs to press ok)
    warndlg(['Port ',com,' OPEN'],'RS_232')  

    % updates the handles structure (example: added pattern_1 to struct)
    guidata(hObject,handles)
    end
    function  intcon1(hObject, eventdata, handles)
    persistent current_state
    persistent L;
    persistent i;
    persistent DATA;
    persistent recieved_checksum;
    % current_state = 0;
    % while (handles.SerPIC.BytesAvailable >= 1)
        this_input = fread(handles.SerPIC,1);

        switch current_state
            case 0 % state 0  wait for HEADER_1
                L=0;
                i=0;
                DATA=0;
                recieved_checksum=0;
                if (this_input == 85)
                    current_state = 1;  
                else 
                    current_state = 0;
                end

            case 1 % state 1  wait for HEADER_2
                if (this_input == 51) %was 170
                    current_state = 2;
                    recieved_checksum = 136;
                elseif (this_input == 85)
                    current_state = 1;
                else
                    current_state = 0;
                end 

            case 2 % state 2  wait for message length
                 MESSAGE_LENGTH = this_input;
                 L=MESSAGE_LENGTH;
                 i=1;
                 current_state = 3;
                 recieved_checksum = mod(recieved_checksum + this_input,255);
            case 3
    %         if (s.BytesAvailable == MESSAGE_LENGTH)
                DATA(i) = this_input;
                recieved_checksum = mod(recieved_checksum + this_input,255);
                i=i+1;
                L = L - 1;
                if L > 0
                    current_state = 3;
                else
                    current_state = 4;
                end

            case 4
                  recieved_checksum = recieved_checksum - this_input;
                  if (recieved_checksum ==0)
                      set(handles.temp_read,'string',[num2str(DATA(1))])
                      set(handles.voltage_read,'string',[num2str(DATA(2))])
                      set(handles.current_read,'string',[num2str(DATA(3))])
                        current_state = 0;
                  else
                      current_state = 0;
                  end

        end
            guidata(hObject,handles)
  end

[Daniel]

is it too messy? i can clean it up a bit if you need. to sum up my question is this: i want to read serial communication continuously but :handles.SerPIC.BytesAvailableFcn = {'@intcon1',handles}; does not seem to work and reference the interrupt to the matching funcion