Describes the cause and action for error messages.
Error Message(English):
vba userform ok cancel buttons
"Ok" command box in userform - Stack Overflow
https://stackoverflow.com/questions/24816465/ok-command-box-in-userform
Cancel Button makes a selection rather than cancelling
https://stackoverflow.com/questions/45839883/cancel-button-makes-a-selection-rather-than-cancelling
Returning a value or Cancel from Excel userform
https://stackoverflow.com/questions/32190506/returning-a-value-or-cancel-from-excel-userform
VBA Excel-How to work with cancel button in the MS Excel ...
https://stackoverflow.com/questions/14398652/vba-excel-how-to-work-with-cancel-button-in-the-ms-exce・・・
Add "Are you sure?" to my excel button, how can I?
https://stackoverflow.com/questions/8569389/add-are-you-sure-to-my-excel-button-how-can-i
Excel VBA を学ぶなら moug モーグ | 即効テクニック | ユーザーフォーム ...
https://www.moug.net/tech/exvba/0090019.html
Excel VBA Userform - Easy Excel Macros
https://www.excel-easy.com/vba/userform.html
フォーム ユーザーフォーム ダイアログ VBA エクセル Excel [エクセルの学校]
http://www.excel.studio-kazu.jp/lib/e1rw/e1rw.html
[ExcelVBA] UserFormの×(閉じる)ボタンへの対策方法いろいろ *Ateitexe
https://ateitexe.com/excelvba-judge-userform-close-button/