what is your data type? is integer? or your data type is Character and you want check data length?
you can check data that user entered with form validation easily
if you want check data length, use 'min char' and 'max char' field in form validation wizard else if your data type is integer, you can use 'Greater than' or 'Less than' fields in validation form wizard
I hope you can solve your problem
this is about custom trigger, i want to make a calculation.. if it wrong.. stop the transaction and rollback everything..
that's the idea.
how to throw the error.. i have the TNG API document.. but can't find the function