Flash MX 2004.
textAttrs.autoKern
Property; a Boolean value that determines whether Flash uses (true) or ignores (false) pair kerning information in the font(s) when it kerns the text.
The following example selects the characters from index 2 up to, but not including, index 6 and sets the autoKern property to true:
fl.getDocumentDOM().setTextSelection(3, 6);
fl.getDocumentDOM().setElementTextAttr('autoKern', true);