Hello friend, thanks for your comment. The reason for the errors might be because of the writing subroutine principles, which sometimes get tricky, and in the video, you shared its link, he may did not explain everything or make some simple mistakes, or you did. The writing subroutine and coding techniques must be learned. You can watch this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-NI2WQZB8730.html or you can see the full package that its link is shared in the description below.