Forms :: How To Link Combobox Between Form And Subform To Only Show Selected Filtered Data

I have a suppliers table and a products table. Two forms, Stock form with combobox to list Suppliers and a sub form with combobox that lists Products.I want to select a supplier from the Stock form and then the combobox in the subform to only list products directly sold by the Supplier.Have dabbled in SQL as follows:

SELECT Products.ProductID, Products.ProductName
FROM Suppliers INNER JOIN Products ON Suppliers.SupplierID = Products.SupplierID
WHERE ((Stocksubform.SupplierID=Stock.SupplierID))
ORDER BY Products.ProductName;