Getting Error

USE MyIMOLTP
 GO
 IF EXISTS (SELECT * FROM sys.procedures
   WHERE name='usp_DemoINMOLTPsp')
 DROP PROCEDURE usp_DemoINMOLTPsp
 GO

 CREATE PROCEDURE dbo.usp_DemoINMOLTPsp
 WITH NATIVE_COMPILATION, SCHEMABINDING, EXECUTE AS OWNER
 AS
   BEGIN ATOMIC
     WITH (TRANSACTION ISOLATION LEVEL
       = SNAPSHOT,LANGUAGE = N'us_english')
   DECLARE @Col1ID int = 1
   DELETE dbo.MyINMOLTPTable
   WHILE @Col1ID < 1000
     BEGIN
       INSERT INTO dbo.MyINMOLTPTable VALUES
         (@Col1ID, 'Data ' + CAST(@Col1ID AS VARCHAR))
     END
   SELECT COUNT(*) FROM dbo.MyINMOLTPTable
   END

 EXEC dbo.usp_DemoINMOLTPsp
 GO