How do you change the format of a video (edited on windows movie maker) to post it on youtube?

Hi

I just learned to use windows movie and me and my friend have a popular wed show at allynjuly.piczo.com also on youtube but i cant post them now because :Failed (invalid file format) : how do i change the format of the movie?How do you change the format of a video (edited on windows movie maker) to post it on youtube?
Convert your videos to FLV formats supported by YouTube with this converter:

http://www.onlineyoutubeconverter.com/hoHow do you change the format of a video (edited on windows movie maker) to post it on youtube?
Open the video at Windows Movie Maker..and then exported the video to .WMV format!!