Creating table of contents in html

This can indeed be done with pure CSS:

ol {
    counter-reset: item;
}

li {
    display: block;
}

li:before {
    content: counters(item, ".")" ";
    counter-increment: item;
}

Same example as a fiddle.

There's quite a number of jQuery plugins to generate a table of contents.

• Look at this one for starters

• Another one here, with ordered lists

Have you seen this post: Number nested ordered lists in HTML

I don't think it can be done without using JS.