Help with how to use user agent in video

Help with how to use user agent in video

    m.videoPlayer.visible = true
    m.videoPlayer.setFocus(true)
    m.videoPlayer.content = selectedItem
 m.videoPlayer.content.VideoDisableUI = true
 m.videoPlayer.content.Live = true
    m.videoPlayer.control = "play"
    m.videoPlayer.observeField("state", "OnVideoPlayerStateChange")

I do not know if I'm correct
m.videoPlayer.content.AddHeader("User-Agent", "Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A543a Safari/419.3")