Hello Mohammad Azzam,
You are right, there is no cancel button to undo demand data. I will go a head and enter a feature request for this issue so that we can add it in our furture releases. However, pump data can be changed by holding Ctrl+Z as long as you don't close the properties dialogue box. Same does not apply for the flextables. So I will also log another feature request for the flextable, but I am not sure if it is a possible solution to add a cancel button in flextables. We hope to bring these changes in future releases. Thank you.
Regards,
Shahzab Bukhari
