Flash MX 2004.
stroke.pattern
Property; a string that specifies the pattern of a ragged line. This property is available only if the stroke.style property is set to ragged (see stroke.style). Acceptable values are "solid", "simple", "random", "dotted", "random dotted", "triple dotted", and "random triple dotted".
The following example sets the pattern property to random for a stroke style of ragged:
var myStroke = fl.getDocumentDOM().getCustomStroke();
myStroke.style = "ragged";
myStroke.pattern = "random";
fl.getDocumentDOM().setCustomStroke(myStroke);