N/search Module
search.lookupFields.promise()
Method Description: Performs a search asynchronously for one or more body fields on a record. Returns select fields as an object with value and text properties. Returns multiselect fields as an object with value:text pairs. The parameters and errors thrown for this method are the same as those for search.lookupFields(options). For more information on promises, see Promise Object.
Returns: Promise Object
Synchronous Version: search.lookupFields(options)
Supported Script Types: All client-side scripts For more information, see SuiteScript 2.0 Client Script Type.
Governance: 1 unit
Module: N/search Module
Since: 2015.2
Search NetSuite - https://system.netsuite.com/app/help/helpcenter.nl?search=search.lookupFields.promise(options)

// Code Example 1

//Add additional code

//...

search.lookupFields.promise({

          type: search.Type.EMPLOYEE,

          id: -5,

          columns : 'email'

          })

     .then(function (result) {

          log.debug({

              details: "Completed: " + result

          });

          // do something after completion

        })

     .catch(function onRejected(reason) {

          // do something on rejection

          });

//...

//Add additional code



//SOURCE: https://system.netsuite.com/app/help/helpcenter.nl?fid=section_4440795405.html