Adobe Extending Flash Professional CS4 - Manual (Page 451)

429 EXTENDING FLASH CS4 PROFESSIONAL
SymbolInstance object
Description
Property; an integer that is equivalent to the Tab index field in the Accessibility panel. Creates a tab order in which
objects are accessed when the user presses the Tab key. This property is not available for graphic symbols.
Example
The following example sets the
tabIndex property of the mySymbol object to 3 and displays that value in the Output
panel:
var mySymbol = fl.getDocumentDOM().selection[0];
mySymbol.tabIndex = 3;
fl.trace(mySymbol.tabIndex);