Download video (audio) from Youtube

Script.scpt

--set urlVideo to text returned of (display dialog "Entrer l'url de la vidéo : " default answer "")
set urlVideo to ""
tell application "Safari"
	set urlVideo to URL of front document
end tell
if urlVideo is "" then
	set urlVideo to text returned of (display dialog "Entrer l'url de la vidéo: " default answer "")
end if
repeat while urlVideo does not contain "https://www.youtube.com/watch"
	set urlVideo to text returned of (display dialog "Entrer l'url de la vidéo: " default answer "")
end repeat
tell application "System Events"
	tell process "Safari"
		open location "http://www.youtube-mp3.org"
		delay 1
		key code 48
		keystroke "a" using {command down}
		key code 51
		delay 1
		keystroke urlVideo
		key code 36
	end tell
end tell
delay 2

tell application "Safari"
	set theScript to "var allChoice = document.querySelectorAll('#content #inner #progress_info.success #dl_link a'); var url = ''; for (var i = 0; i < allChoice.length; i++){if (allChoice[i].getAttribute('href').indexOf('create') != -1){url = allChoice[i].getAttribute('href');}} window.open(url);"
	do JavaScript theScript in first document
end tell