A customer asks you to make the following updates to a form:When Caller field is...

To manipulate a form in real-time while the user is viewing it (the browser session), you use a Client Script.

1. Requirement Analysis:

" When Caller field is populated... " : This describes an event happening in the browser before the data is sent to the database. This requires an onChange Client Script. When the " Caller " value changes, the script executes (often using GlideAjax to fetch server data) to populate the " Location " field dynamically.

" Add notice... when record is submitted " : This describes an action triggered when the user clicks " Save " or " Submit. " This requires an onSubmit Client Script. The script can validate data or display a message using g_form.addInfoMessage() before the form data is finalized.

2. Why other options are incorrect:

A (UI Script): UI Scripts are typically used to create reusable libraries of JavaScript that can be called from other scripts, or for global UI modifications. They are not the standard tool for specific table-level form logic like " When Caller changes on Incident. "

B (Server script): Server scripts (like Business Rules) run after the browser sends data to the database. While a Business Rule could set the location after the fact, it cannot update the screen in real-time while the user is still typing, nor can it easily show a message " at the top of the page " during the submit process in the same way.

D (JavaScript): While Client Scripts are written in JavaScript, " JavaScript " is a language, not the specific ServiceNow feature/object used to configure this behavior.