Is it possible to add a custom button to a DNN instance?  What I'm after is to have a dialog box pop up, ask for an image url and then wrap that url in the html necessary to display the image.  I've dug through the documentation and i'm a little confused as to how I'd do it..  What I want is similar to this example..

 

http://www.cutesoft.net/example/howto/AddDialogs/vb/create_a_custom_dialog.aspx