Lock table during update in linq to sql

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C#

C#4.0

Good morning all,
my app working with a table with one record in it. The record is used to keep the next available unique id. The way the system is developed, to get the next id you lock the table, create a new record with the id incremented by 1. Then delete the old record and unlock the table.

I can not figure out how to lock a table with using linq to sql and see a way to both get the id and update the record in one statement so the locking is done for me.

I need to find a way to get the ID and increment it and be sure no one else managed to get the ID also before i increment it.