Service Portal auto populate fields after user name selected

[Moedeb]

I have a requirement for a couple of fields to be populated with the appropriate information once a customer adds the name of the 'owner' of a dashboard - that persons email and department needs to then be added to the appropriate fields.

I have checked a number of forum posts similar, tried most of them and still can't get it to work, so here I am asking directly.

So based on the Owner name being added (which shows as the first name and surname - eg: Joe Bloggs) - note: it is almost certainly not going to be the name of the user entering the details.

owner_section would map to the 'Department' field

owner_email would map to the 'email' field

I believe all are available through sys_user

Also as a side question - is it possible to allow free text in a reference field if someone needs to enter something that is not available to select? 

If someone could let me know how to do this I'd certainly be grateful.

[Shweta KHAJAPUR]

Can you give more details about the field? are these fileds populated from widget or is this some catalog?

[Moedeb]

Sorry this is a catalog item - so a user chooses the owner name from the active user list in our instance.

[Shweta KHAJAPUR]

You can use onChange catalog client script to populate remaining two.

[Moedeb]

Yes I realise that an on change script is the most likely answer, but I have not been able to get any of the scripts I've found on here to work, so I'm hopeful someone can provide me with the script I can use?