This is one method.. However in terms of website performance, it will be making website heavier, since the banner (which is an image) will be on every page. And if i decide to add more pages to my website like 20 or 30 more, this wouldn't be a good option.
Is there a way to create a template sort of thing if possible at this stage (when now I already have 20+ pages of my website) and marge that template with my website pages. In the template I can put the banner and set it at its right location?