您不能，浏览器不允许，句号。

You can't, browsers won't allow it, full stop.

_{您可以，如果您编写的浏览器/ ActiveX / Java插件具有这种访问权限，并让用户安装了该插件，但是请不要 。}

_{You could if you wrote a browser/ActiveX/Java plugin that has that kind of access and got the user to install it, but please don't.}