Using ScriptRunner to Check Updates of a Field Using Listener

[ServiceDesk]

So agent goes to the queue and opens up an existing request.  The request has numerous fields and the agent updates a custom field (dropdown box), immediately a pop-up screen appears asking if the agent wants to updates the custom field as the security level of the request will change after updating this custom field.  I am not sure if this is achievable using ScriptRunner :

i.  Check a custom field is updated.

ii.  Shows a pop-up screen to confirm the changes on the custom field

iii.  If user confirm changes, update the security level of the request