MACROMEDIA FLASH 8-EXTENDING FLASH Manual page 488

Description
Method; inserts a keyframe at the specified frame. If you omit the parameter, the method
inserts a keyframe using the playhead or selection location.
This method works the same as except that the inserted
timeline.insertBlankKeyframe()
keyframe contains the contents of the frame it converted (that is, it's not blank).
Example
The following example inserts a keyframe at the playhead or selected location:
fl.getDocumentDOM().getTimeline().insertKeyframe();
The following example inserts a keyframe at Frame 10 of the second layer (remember that
index values are different from frame or layer number values):
fl.getDocumentDOM().getTimeline().currentLayer = 1;
fl.getDocumentDOM().getTimeline().insertKeyframe(9);
timeline.layerCount
Availability
Flash MX 2004.
Usage
timeline.layerCount
Description
Read-only property; an integer that represents the number of layers in the specified timeline.
Example
The following example uses the variable to store the number of layers in the current
NumLayer
scene:
var NumLayer = fl.getDocumentDOM().getTimeline().layerCount;
timeline.layers
Availability
Flash MX 2004.
Usage
timeline.layers
488 Objects