Invalid URL or URL Null. Re-Enter The Video URL, Plz.

I have java, its enabled and i'm using firefox 3, is there anything you can suggest?
Anything you can give me would be a big help.

1. Find the video that you want.
2. Find the address bar and the url.
3. This must be a youtube video to do this. First, add “kiss” (without the quotation marks) before youtube. So “ http://www.youtube.com/watch?v=?????????” would become http://www.kissyoutube.com/watch?v=?????????
4. Now click on the download now button. When you save it, remember to put “.flv” after the name (without quotes). Save it to somewhere that is easy to locate, such as your desktop
5. Now go to http://media-convert.com/
6. Browse for your file, and then click what type of file you want it to become. There are many types. You can choose for it to become a movie, sound, ringtone (PCM + Polyphonic), and a ringtone (monophonic +Polyphonic) if your converting videos. You can also convert text, images, sounds, and data.
7. Click “I accept the terms” and OK.
8. Your video will start loading.
9. After a while, it will go to another screen and continue its loading. This will only take a few minutes, depending on the speed of your computer.
10. When your done, click download. Save it.

CONGRATS! You have just “taken” a video from youtube without any programs!