To get the last enter auto generated id use
USE tempdb
GO
CREATE TABLE TZ (
Z_id int IDENTITY(1,1)PRIMARY KEY,
Z_name varchar(20) NOT NULL)
INSERT TZ
VALUES ('Lisa')
INSERT TZ
VALUES ('Mike')
INSERT TZ
VALUES ('Carla')
SELECT SCOPE_IDENTITY() AS [SCOPE_IDENTITY] FROM TZ
SCOPE_IDENTITY() return the last id value being autogenerated