Open A Form And Show A Specific Records?

I have a dataset called KeyData made up of two tables Customers and Orders.

I have two forms, one named MainForm that shows records from Customers in details view and the related Orders shown in GridView called OrdersDataGridView. The other form is called OrdersForm and is populated with the Orders table from the keydata dataset and shows records in details view.

When I navigate the MainForm customer records the correct orders are shown in the OrdersDataGridView. So far so good.

Here's the code that was generated when I dropped the tables within KeyData dataset onto the MainForm:

Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'KeyData.Orders' table. You can move, or remove it, as needed.

[Code]....