how to implemet binding context

[dhol]

Hi I want to know abt binding context and its functions. I have two tables. one is the parent table and another is the child table. I have read this tables to a dataset. and create a relation for a column say customer_id (which exissin both tables). Then i have to add two datagrids and bind one datgrid to the parent table and another datagrid to child table. No wi have to implement the binding context add abutton to the form, and inthe click event of that button increase the binding context by one. then we can see taht according to the parent tables customer_id in the grid, it will show that id in the child table grid. pls anyone help it to do. can anyone give some sample code and explain to me in clearly how this works. j o h n