var createCustomer = record.create({
                        type: record.Type.CUSTOMER,
                        isDynamic: false,
                        defaultValue: null
                       });
                log.debug('create customer',createCustomer);
                createCustomer.setValue({
                         fieldId: 'firstname',
                         value: context.firstname
                         });
                createCustomer.setValue({
                            fieldId: 'lastname',
                            value: context.lastname
                            });
                createCustomer.setValue({
                                fieldId: 'email',
                                value: context.email
                                });
                createCustomer.setValue({
                                fieldId: 'phone',
                                value: context.phone
                                });
                //submit the record
                var id = createCustomer.save();
                return id;			
                }

Creating a customer record it's getting created, but can't see First and last name.