Linq puts the identity (Id) of the inserted record into the inserted instance object during the Submit operation. After calling Submit get the Id.
Example:
public void HandleInsert(string Handle, int CompanyId, ref long HandleId)
{
DataClasses1DataContext DbObj;
PhraseHandle HandleObj;
using (DbObj = new DataClasses1DataContext())
{
HandleObj = new PhraseHandle();
HandleObj.PhraseHandle1 = Handle;
HandleObj.CompanyId = CompanyId;
DbObj.PhraseHandles.InsertOnSubmit(HandleObj);
DbObj.SubmitChanges();
HandleId = HandleObj.PhraseHandleId;
}
}