def check_load_file(filename, files):
    if not os.path.exists(filename) or not os.path.isfile(filename): 
        print 'Error can not find the specified file'
        return

    filetype = filename.split('.')[1]
    
    if filetype == 'csv':
        csv_data = CSVData(filename)
        csv_data.parse_vectors()
        files.append(csv_data)
    elif filetype == 'txt':
        txt_data = TXTData(filename)
        txt_data.read_document()
        files.append(txt_data)
    else:
        print 'Error unrecognized file type ', filetype
        return

    print 'Parsed file: ', filename