Is it possible to popup a warning/error message when a same item id for the same customer is created

 Hello all,

One of my user was able to create a same item id for the same customer in the pending item page. What happened is, the amount is added to that same item.

Is there a configuration or option that we can popup a warning or error message to prevent that?

Ex:

1) Go and create a pending item id TEST1 for 100$
2) Run AR UPDATE
3) Go and verify the balance for item id TEST1 it should be 100$
4) Now create a new pending item with TEST1 as item id for 50$
5) Run AR UPDATE
6) Go and verify the balance for item TEST1. It should give you 150$