3.1. AJAX Custom Field Overview
The AJAX Selection Field is a dynamic way to enter information into a request. The AJAX Selection Field is similar to a regular text custom field, however, its value may be set by a drop down list created dynamically (in real time) through the use of AJAX (a web scripting technology). This allows the drop down list to be custom to the specific customer or even that specific request. It also proves to be useful in situations where the values of a drop down list may change periodically as it eliminates the need to edit the custom field values in HelpSpot.
When an AJAX Selection Field is used all the information about the request is passed to a script you write (outlined in the implementation guide). Your script can use that information to return drop down list items specific to that request.
One sample use of this is to return a list of billing codes that are specific to a customer or category.
Another feature of the AJAX Selection Field is that it can be used as a search box. Along with information on the request, your script is also sent the value of the AJAX Selection Field. So if you enter a search term in the text box and then click the AJAX Selection field button, the script can use that search term to produce the drop down list of results.