I am very sorry, as I could not display the code without it disappearing on the forum.
I first used an iframe with the source as /htdocs/1SlenderWeb.html, and then tried to embed it with /htdocs/1SlenderWeb.html as well.
Did you add tags around it to make it show up as code? This forum supports formatting posts with BBCode, Markdown or raw HTML. So if you dump HTML directly into your comment, the forum assumes you’re using HTML to format your post, and will parse your code.
If you want your HTML to show as source code, you need to add code tags around them in BBCode or Markdown.