You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: spm_api_erp.m
    path of file: ./repos/bspm/thirdparty/spm12/toolbox/dcm_meeg
    
    the code of the file until where you have to start completion: function varargout = spm_api_erp(varargin)
% SPM_API_ERP Application M-file for spm_api_erp.fig
%    FIG = SPM_API_ERP launch spm_api_erp GUI.
%    SPM_API_ERP('callback_name', ...) invoke the named callback.
%__________________________________________________________________________
% Copyright (C) 2005-2014 Wellcome Trust Centre for Neuroimaging
 
% Karl Friston
% $Id: spm_api_erp.m 6644 2015-12-12 14:53:37Z karl $
 

%-Launch GUI
%--------------------------------------------------------------------------
if nargin == 0 || nargin == 1
 
 
    
function BMS_Callback(hObject, eventdata, handles)
%spm_api_bmc
spm_jobman('Interactive','','spm.dcm.bms.inference');
 
 
% --- Executes on selection change in ERP.
%--------------------------------------------------------------------------
function handles = ERP_Callback(hObject, eventdata, handles)
 
% get analysis type
%--------------------------------------------------------------------------
handles = reset_Callback(hObject, eventdata, handles);
switch handles.DCM.options.analysis
 
    % conventional neural-mass and mean-field models
    %----------------------------------------------------------------------
    case {'ERP'}
        Action = {
            'ERPs (mode)',...
            'ERPs (sources)',...
            'coupling (A)',...
            'coupling (B)',...
            'coupling (C)',...
            'trial-specific effects',...
            'Input',...
            'Response',...
            'Response (image)',...
            'Scalp maps',...
            'Dipoles'};
        try
            set(handles.Nmodes, 'Value', handles.DCM.options.Nmodes);
        catch
            set(handles.Nmodes, 'Value', 8);
        end