procedure deleteSubscriber(NumberOfSubscriber: TNumber);
const
    DELETER: ansichar = '/';
var
    SourceFile: TBinaryFile;
    Offset: integer;
    NumberOfRecord: LongWord;
    ArrayOfRecordNumber: TNumber;
    DeleterArray: array[1..RECORD_SIZE] of ansichar;
begin
    fillchar(DeleterArray, RECORD_SIZE, DELETER);
    assign(SourceFile, getCurrentDir + '\' + FILE_NAME);
    reset(SourceFile);
    Offset := NumberOfSubscriber * RECORD_SIZE;
    seek(SourceFile, Offset);
    blockWrite(SourceFile, DeleterArray, RECORD_SIZE);
    closeFile(SourceFile);
end;