currentSet

currentSet
Not in SeaMonkey 1.x
Type: comma-separated list of strings
Holds a comma-separated list of the IDs of the items currently on the toolbar. For spacers, separators, and flexible spacers the following strings are used instead of IDs: "spacer", "separator", "spring". An empty toolbar has a currentSet value of "__empty".
You may change the current set of items by setting this property. Be careful, as setting this property doesn't automatically update the currentset attribute.