I found it hard to delete a record by script from the information register , it's not specified in the "a practical developers guide" book or in the 1C enterprise help ... I think 1C is hard to learn for not Russian people

You simply need to understand some concepts.
If you need to delete a single record, you can use Delete() method of your information register record manager. If you need to delete a bulk of records, you need to create a record set, remove those records from it and write it.

Use

InformationRegisterRecordManager.Delete()

For example:

   Prices = InformationRegisters.PriceList.CreateRecordSet();
   Prices.Filter.Product.Set(ProductRef);
   Prices.Filter.Period.Set(BegOfMonth(Month));
   Prices.Read();
   For Each Price In Prices Do
       Prices.Delete(Price);
   EndDo;
   Prices.Write();

thanks Stephanie Elliott, I'll try it ... 1C is a great language I really want to learn it, but  i think there is lack of examples ... i know there is forums in Russian and Turkish gives a lot of examples but I can't speak those languages ... if you want to go public i think you should take care more of English speakers ... I'm from Syria but now living in turkey ...  in syria we've never heard about 1C, in turkey it's popular a little bit

Dmitry Shcherbakov, thanks a lot for helping

You're welcome. This site is to compensate this lack.

Stephanie Elliott, I appreciate your efforts ... and I'm sorry for the huge amount of questions i ask