wxruby - Can I update the options of a ComboBox

Question

I have a ComboBox that I fill dynamically by what the user enters in it.

ursls = LOAD_FROM_FILE("urls.txt")
my_combobox = ComboBox.new(self, -1, '', DEFAULT_POSITION, DEFAULT_SIZE, urls )

And when somebody submit I save the new url

def submit(url)
...
APPEND_TO_FILE("urls.txt",url)
...

This works great, but the ComboBox is only updated when I restart the application. I would like to have it update on submit

my_combobox.OPTIONS << url

I know I could create a new Combobox everytimes somebody does a submit, but it seems like such a waste of resources.

The documentation gives me nothing
http://wxruby.rubyforge.org/doc/combobox.html

If you can help, I would appreciate it.