     private function inputManager_flowOperationBeginHandler(
                         event:FlowOperationEvent):void
     {
-        //trace("flowOperationBegin");
+        //trace("flowOperationBegin", "generation", textFlow.generation);
         
         var op:FlowOperation = event.operation;
-
+   
+        // The text flow's generation will be incremented if the text flow
+        // is modified in any way by this operation.
+             
         if (op is InsertTextOperation)
         {
             var insertTextOperation:InsertTextOperation =

    {
        var format:Object = {};
        
        // Switch to the EditManager.
        var priorEditingMode:String = editingMode;
        editingMode = EditingMode.READ_WRITE;
        var selectionManager:ISelectionManager = getSelectionManager();
                
        // This internal TLF object maps the names of format properties

    private function inputManager_flowOperationEndHandler(
                        event:FlowOperationEvent):void
    {
        //trace("flowOperationEnd", "generation", textFlow.generation);
        
        // Paste is a special case.  Any mods have to be made to the text
        // which includes what was pasted.
