An easy-to-grasp HTML box
Sometimes a simple HTML box containing the code to be copied is far better than elaborate JavaScript-based boxes that don't work in every browser (some people disable JavaScript for security reasons - you can't blame them).
Text-based HTML code fields are a much more user-friendly alternative, and they're also easy ebay database to implement. All you need to do is enter your code between the following tags on your page:
<pre>[insert your HTML code here]</pre>
And voilà !
2. A way to say "thank you"
Tell satisfied visitors that one of the best ways to help your website grow is to use a backlink with the HTML backlink code on their web pages.
Don't be pushy. Just say it will help, and explain how it will with a simple bulleted list or a link to another page where you explain the importance of backlinks for your website to help it establish a position in search engines.
What I did for my mom blog was add my HTML codes under a heading "Would you like to help this website?" where I made it clear that I wanted the blog to gain visibility and traffic. The codes follow this statement.