If i want to use a crappy search engine, i will choose a crappy one. Ask.com is crap search engine and a shitty company which takes over your computer without permission. If ask.com trojanizes your browser search engine, you have to use the Firefox configuration editor to get it back.
In the URL box type: about:config There will be a ton of name/value pairs which specify all sorts of configuration items. Look for: keyword.url and change it back to: http://www.google.com/search?q=
Now when you type in something to search in the URL box, you will get the awesome search results of Google and not the crappy Ask.com results that you never asked for. Pun intended. Fuck you Ask.com