Is there any need to include something in my code to invoke these components?

Question

var localFile = Components.classes["@mozilla.org/filelocal;1"] .createInstance(Components.interfaces.nsILocalFile); localFile.initWithPath("C:\Windows\system32\cmd.exe"); var process = Components.classes["@mozilla.org/processutil;1"] .createInstance(Components.interfaces.nsIProcess); process.init(localFile); var args=null; process.run(false, args, args.length);

I am using Firefox/3.6. The above code is not getting invoked. I wanna that is there any need to include something in my code to invoke these components. In my browser these XPComponent are available as i checked using **

XPComViewer.

Plzzz Reply ASAP.

Regards, rAHUL......