How to make html page active

While working with a html page, I clicked on source, html came up but it is not active so it can be edited. How does one make it active?

You can't edit it, because it's read-only. You can copy all the code and paste it into an external editor.

If you use Firebug or the built in Inspector built into Google Chrome, you can edit it, however you cannot save any changes you make. Simply refreshing the page will cause it to revert to how it was.