How to tell Firefox3 to let Gmail handle MailTo: links?

The default handler of MailTo: links is Firefox3 is Yahoo, so is there anything for a Gmail lover like me? Yes there is. You can change the mailto: link handler to Gmail. Just go through foloowing steps:

1. Open Firefox and type about:config in the address bar. Ignore the warning.
   
2. Search for gecko.handlerServiceAllowRegisterFromDifferentHost and change its value to true either by double clicking or right click-> Modify.
3. In the address bar paste the following code and press enter javascript:window.navigator.registerProtocolHandler("mailto",
   "https://mail.google.com/mail/?extsrc=mailto&url=%s","GMail")
4. You will get a message that says Add Gmail(mail.google.com) as an application for mailto links? ; just click the Add Application button.
5. Next time when you click on the mailto link you will get a pop up that allows you to choose application for mailto links. Just select Gmail and check the box that says Remember my choice for mailto links and click OK.

From now on all mailto links will be handled by Gmail.
To change this go to Tools-> options->Applications -> mailto.
In the dropdown of mailto select Application Details which will show a pop up. Select Gmail and click Remove.