Adding option fields for Notices

[Trombones13]

Rather than dealing with HTML each time I want to create a new Notice, I would like to add custom fields for options such as a background image:

Unfortunately, I can't figure out how to do that--I've done it with Options before while in debug mode, but it looks like the same idea doesn't work here. Could someone point me in the right direction (I presume I'd need to edit a core file, but I'm not sure which one)? Thanks!

 

[Jake Bunce]

Adding a new field like that requires a proper addon. It's not a simple change (unlike in the Options). I would stick with the HTML.

 

[Trombones13]

It's not a simple change (unlike in the Options).

It never is, is it? haha Oh, well; thanks!