function[obj] = importData(obj, varargin)
if (nargin == 1)
    if (isempty(obj.filename))
        error('  Filename has not been set')
    end
else
    obj.datafile = varargin{1};
end

[base filename ext] = fileparts(obj.datafile);

if strcmp(lower(ext), '.edf');
    obj.readEDF;
end

if strcmp(lower(ext), '.asc');
    obj.read_ASC;
end

if strcmp(lower(ext), '.gazedata');
    obj.read_gazedata;
end

end