Time for two SQL Queries

DECLARE @t1 DATETIME;
DECLARE @t2 DATETIME;

SET @t1 = GETDATE();
SELECT /* query one */ 1 ;
SET @t2 = GETDATE();
SELECT DATEDIFF(millisecond,@t1,@t2) AS elapsed_ms;

SET @t1 = GETDATE();
SELECT /* query two */ 2 ;
SET @t2 = GETDATE();
SELECT DATEDIFF(millisecond,@t1,@t2) AS elapsed_ms;