You can set the warn prefs on the about:config page to true via the right-click context menu or toggle the value with a double left-click.

• browser.showQuitWarning, see http://blog.zpao.com/post/3174360617/about-that-quit-dialog
• browser.tabs.warnOnClose, see http://kb.mozillazine.org/About%3Aconfig_entries
• browser.warnOnQuit , see http://kb.mozillazine.org/browser.warnOnQuit
• browser.warnOnRestart , see http://kb.mozillazine.org/browser.warnOnRestart

Thank you!! My beloved dialog box is back and you are the GREATEST!!!

The first link with the link to the comments on the code was all it took.

thanks very much for the information ~

I've tried all three:

browser.showQuitWarning, set to true browser.tabs.warnOnClose, set to true browser.warnOnQuit, set to true

I even set to true: browser.warnOnRestart;true

and it still doesn't work. Any idea? This is so frustrating. How about just making this a simple preference in the main preferences dialogue box. Certainly we're not the only one with that problem. I've been reporting this for a very long time now.

Nicolas

Try to use "Firefox/File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit") to close Firefox if you are currently doing that by clicking the close X on the title bar.

The first solution, by Cor-el, worked for me. Thanks again, Cor-el!!! I believe I had to go to the about:config page to do it.