Converting .wav files to mp3's using itunes?

I Had a flac file on my computer and i was looking to play it in itunes. I managed to convert the flac file to .wav using winamp following this advice http://www.simplehelp.net/2006/08/14/how-to-convert-flac-files-to-mp3-using-windows/. But when it tells u to change it to mp3 encoder from the importing using list in itunes i cant because i can't find this tab on my itunes. please help