SuiteScript 2.1 User Event Script Skeleton

/**
 * @NApiVersion 2.1
 * @NScriptType UserEventScript
 * @NModuleScope SameAccount
 * @name Sales Order Credit Check
 * @author Your Name
 * @version 1.0 (2026-10-20)
 */
define(['N/record', 'N/log', 'N/runtime'], (record, log, runtime) => {

  const beforeLoad = (context) => {
    try {
      if (context.type !== context.UserEventType.VIEW) return;
      // context.form is available here for adding fields or buttons
    } catch (e) {
      log.error({ title: 'beforeLoad failed', details: e });
    }
  };

  const beforeSubmit = (context) => {
    try {
      const rec = context.newRecord;
      const value = rec.getValue({ fieldId: 'custbody_credit_hold' });
      log.debug({ title: 'beforeSubmit SALES_ORDER', details: 'value=' + value });
      // Validate or set fields here. Do not call rec.save() in this entry point.
    } catch (e) {
      log.error({ title: 'beforeSubmit failed', details: e });
      throw e;
    }
  };

  const afterSubmit = (context) => {
    try {
      if (context.type === context.UserEventType.DELETE) return;
      if (runtime.executionContext === runtime.ContextType.MAP_REDUCE) return;
      const rec = record.load({ type: record.Type.SALES_ORDER, id: context.newRecord.id });
      log.audit({ title: 'afterSubmit', details: 'Loaded ' + rec.id });
      // Side effects such as creating related records or calling an integration go here.
    } catch (e) {
      log.error({ title: 'afterSubmit failed', details: e });
    }
  };

  return { beforeLoad, beforeSubmit, afterSubmit };
});

Script file: upload to the File Cabinet under SuiteScripts.
Script record: Customization > Scripting > Scripts > New, select the file.
Deployment: set Applies To to the record type, Status to Testing, Audience to your test role.
After testing: change Status to Released and widen the audience.