def create_files
    f1 = datastore['TXT_FILE'].empty? ? 'regasm_regsvcs.txt' : datastore['TXT_FILE']
    f1 << '.txt' unless f1.downcase.end_with?('.txt')
    f2 = datastore['SNK_FILE'].empty? ? 'key.snk' : datastore['SNK_FILE']
    f2 << '.snk' unless f2.downcase.end_with?('.snk')