Pass values from reference field to a textarea field on UI Page HTML

[Dazler]

Hi,

I created a UI page that displays for a user to fill out. 

The Milestone field is a reference field and once the user select the milestone.  I want the Status and description field to auto-populate the values from the Milestone select.  There are 2 fields on the table that is being referenced in the Milestone field.

Here is my HTML

<g:ui_reference mandatory="true" name="miles" id="miles" table="x_exf_it_issue_man" query="iss_number=${JS:sysparm_iss_id}" completer="AJAXTableCompleter" oninput="milestoneModal.milestoneOnChange()" onchange="milestoneModal.milestoneOnChange()"/>

How can I retrieve those 2 column values from the reference field and populate the Status and description fields?

[Markus Kraus]

@Dazler Please take a look at my (the very first) answer to your post. I've added the full Code you need to implement your requirement.