Adobe Extending Flash Professional CS5 - Manual (Page 325)

303 EXTENDING FLASH PROFESSIONAL
Frame object
Last updated 5/2/2011
This property is ignored if the frame doesn’t have custom easing applied.
Example
The following example specifies that a single custom ease curve should be used for all properties of the first frame on
the first layer:
var theFrame = fl.getDocumentDOM().getTimeline().layers[0].frames[0]
theFrame.useSingleEaseCurve = true;
See also
frame.getCustomEase() , frame.hasCustomEase , frame.setCustomEase()