app crashes with backspace key

[snufas]

hello when ever i try to delete time values using backspace key or eather by selecting them with ctrl +a to delete all values the program shuts down. the fix for this moment is to select the values with ctrl + a and type new once without deleting old onece so it is replaced. you are probably not checking something if i am trying to delete values the fields can't be emty or the value always must be 0.

i am guessingbackspace key actually deletes the value and you are not handeling null values in the fields.

to test that for your self pres backspace key few times and you see what wil happin.
good app with good GUI otherwise.