text: CREATE PROCEDURE p_AddTownToTowns (@townName VARCHAR(50))
  AS 
  BEGIN
  BEGIN TRANSACTION
  	DECLARE @IsContainsTown INT = (SELECT COUNT(*) FROM Towns
  								  WHERE TownName = @townName)
  	IF(@IsContainsTown != 0)
  	BEGIN
  		ROLLBACK
  		RETURN
  	END
  
  	INSERT INTO Towns(TownName)
  	VALUES (@townName)
  	
  	COMMIT
  END