You can activate a lightbox to use for your links, or other special pages as needed by activating the Thickbox plugin.
From your control panel, go to Website Settings, then go to Enable JQuery Plugins (Advanced Users).
Select the plug-in Thickbox, then click to save.
Now you can add a link to your site, such as the sample below to open a link in a lightbox window.
More information on using this plugin can be found here: