Notification to the end users about a newer version

I am having an application that will be installed on various machines. Now if i have a newer version than the installed one, i need to inform the users that an update is available. An update that shows up in Mozilla Firefox about a newer version,similar to that. Is this possible to implement?? Or how those Firefox guys implementing that feature? My application has been implemented using Qt 4.4. But i guess this doesn't conform to a specific programming language. I开发者_运维知识库 have virtually no idea about implementing this so any ideas regarding this are welcome.

you need a web site page, like http://yourapp.com/version and place version number in this page.

each time your app runs, check this page(quietly), if found version > current version, then open a confirm window.