how can I add the "allow clipboard" functions to a site in firefox 7?

I've followed the steps from https://developer.mozilla.org/en/Midas/Security_preferences to enable the clipboard functions in Firefox 7. I would like to add the function to the Admin section (Control Panel) of my website. I had to create the user.js file as it did not exist. The following are the contents of my user.js: user_pref("capability.policy.policynames", "allowclipboard"); user_pref("capability.policy.allowclipboard.sites", "http://www.pcxpresstune.com"); user_pref("capability.policy.allowclipboard.Clipboard.cutcopy", "allAccess"); user_pref("capability.policy.allowclipboard.Clipboard.paste", "allAccess"); I re-opened Firefox, opened my Control Panel, while editing an article I tried to use the "cut" button, but received the message that clipboard functions are not allowed in Firefox.