Hi:

Perhaps you can do it with the "AVANT_MOD" object action:
https://online-help.sageerpx3.com/erp/12/wp-static-content/static-pages/en_US/MODEL/AVANT_MOD.htm

Thanks Nacho Alferez

I got the idea, but can you explain to me where should I add specific script?. Because I did check in Object action and Sage default doesn't allow me to modify or add specific script. Here's example of Sale invoice object (SIH). 

Hi Giang:

First thing you have to do is create the "SPESIH" process. Where can you do that? I use eclipse to write 4GL code, but in order not to make this answer complicated, just go to the path: Development -> Script dictionary -> Scripts -> Script editor.

Type "SPESIH" in the "File name" field and then you can begin to write your code. As a template, the following code can be usefull for you:

$ACTION
  Case ACTION
    When "AVANT_MOD" : Gosub AVANT_MOD
  Endcase
Return

$AVANT_MOD
  « Write your code »
Return

Don't forget to compile (the compile button does two things: save and compile the file). If it returns an error, correct the code.

Remember that if you want to interrupt the modification of a record, you will have to set OK=0. Also, It would be helpfull if to set GPE=1, just to make sure we won't go through the standard SUBSIH process.

And if you want to develop in X3, I recommend a training course.

Thanks,

Nacho Alférez.