create proc mytest

as

begin

 DECLARE @res INT

    EXEC @res = sp_getapplock

                @Resource = 'mytest',

                @LockMode = 'Exclusive',

    @LockOwner = 'Session'

 if @res = 1

 begin

  EXEC @res = sp_releaseapplock

                            @Resource = 'mytest',

       @LockOwner = 'Session'

   return;

 end

 PRINT 'get lock'

 waitfor delay '00:01'

        EXEC @res = sp_releaseapplock

                            @Resource = 'mytest',

       @LockOwner = 'Session'

        PRINT 'release lock'

end