Show new properties at runtime in PropertyGrid control

Question

I have a grid which displays a list of Orders. When I double click a row it displays the properties of the Order in a PropertyGrid control. The PropertyGrid.SelectedObject property is then set with an object instance of Order that contains all of the properties.

However, users can define their own properties for an Order and at runtime these new Properties are added to the grid as new column headers. What I want to know is how do I update the PropertyGrid control to show these new properties.

Thanks in advance!!!