sharepoint online – If somebody choose a value from choice field in NewForm, then pop-up window or notification is displayed

Is it possible in SharePoint (I use Classic Experience) to display a notification, when somebody choose particular value from choice field in New Form?

For example, I’ve a choice field in New Form, called “Country” – there is a list of values to choose USA, Europe, Asia.

If someone choose “Asia” then SharePoint display a pop-up or any notification windows about the content “Country is chosen”.

Is it possible with a little coding in JavaScript?