Of course you can't, however, since your options are currently limited to sitting in front of CNBC waiting for your stock to come across the ticker tape, you need to find a way to get real-time stock quotes on line. However, even this can be a daunting task. Most real time market data services require a recurring fee which can run anywhere from 10 to 50 dollars a month!
The other option you have is through your brokerage account. Unfortunately, even today many brokerage accounts don't offer real-time quotes like they should. They hype themselves up as being the greatest thing since sliced cheese with all of their services and fancy commercials, but oftentimes they can't even give you the basic information you need. Unless, of course, you're willing to pay extra for it.
Thankfully, there are more options for free stock quote services starting to emerge on line. The ones that I've seen often require you to sign up with an email address in hopes that they can sell you on a product or service later on. Luckily, all you have to do is check the No Thanks box when they ask you if you want to receive offers and you won't have to put up with any spam mail while still getting free stock quotes!