You need to find the name of the desired font:
var fonts = Font.enumerateFonts(true);
fonts.sortOn("fontName", Array.CASEINSENSITIVE);
for each(var f:Font in fonts)
trace(f.fontName);
"TradeGothic". , "TradeGothic Light Oblique", :
formatT.font = "TradeGothic Light Oblique";
, , , (. ). , :
textItem.embedFonts = true;
btw, , false :
var embeddedFontsOnly = Font.enumerateFonts(false);