Search and replace while editing page

I’m just trying to do a simple search and replace while on the “Edit Page” screen, in either the “Visual” or “Text” mode. I can’t duplicate this, but at one point I believe I was typing Ctrl-F and it came up with a screen for searching and replacing, but the screen would freeze, and I could never enter text in either the search or replace fields. Now when I do Ctrl-F it just comes up with the browser’s standard “Find” screen without the option to do a replace (I’m using Internet Explorer). Is there a simple way to perform a search and replace function without copying and pasting the page contents into another text editor?

Thanks.