Flash MX 2004.
shape.beginEdit()
None.
Nothing.
Method; defines the start of an edit session. You must use this method before issuing any commands that change the Shape object or any of its subordinate parts.
The following example takes the currently selected shape and removes the first edge in the edge array from it:
var shape = fl.getDocumentDOM().selection[0];
shape.beginEdit();
shape.deleteEdge(0);
shape.endEdit();