Convention

There are Two Rules you must know about DC.BindingRecordset:

Textbox Controls which located in your data form must have the same names as their Fields names in related table and Columns Controls which involved in your datagrid must have the same names as their Fields names in related table for details

Textbox Controls which located in your data form and not have related Field in related table must begin with "x" or "X" character , you can not name related Textbox Control with "X" or "x" prefix