Error #2009: This method cannot be used on a text field with a style sheet

1

I keep getting this errors when i put the style in (texts in red)

for (var i:int = 0; i < 49; i++)
{
txtSong.appendText(sname(_xmlList*[“songTitle”] + " "));
txtSong.appendText(sartist(_xmlList*[“songArtist”] + "
"));
}

i was wondering why is it not working?

Thanks