<%@ reference control="~/VideoPlayer.ascx" %>
(2) Expose your private variables as public properties, using setters in the control. (You can also expose Web Control values in your user control through these setters.)private int id; public int Id { set { id = value; } }(3) The opposite also works in the control, but you cannot do both. You'll get a circular reference error.
<%@ reference page="~/Default.aspx" %>Also, you're probably already are aware of this, but your user control should inherit from mmUserControl, and here's how you register MM.NET business objects in the user control:
category = (Category)BusinessWebPage.RegisterBizObj(new Category());