toggle between master page and iframe?

Hi,
Is it possible to toggle the master page view between iframe and masterpage view depending on which link is clicked?
Say if I click an asp link it should be opened in an iframe and the masterpage part for the content (<asp:ContentPlaceHolder ID="MainContent" runat="server">blabla</asp:ContentPlaceHolder>) is "hidden" and the iframe shown, if an aspx page link is clicked it should be the other way round: hide the iframe and show the content part of the master page.

Thx in advance,
Pascal