import wx
def onListBox(self):
    dlg = wx.MessageDialog(None,\
    event.GetEventObject().GetStringSelection(),'A Message',wx.OK)
    dlg.ShowModal()

app = wx.App()
frame = wx.Frame(None,title = "Vi du ListBox", size=(300,150))
panel = wx.Panel(frame,-1)
languages = ['C', 'C++','Java','Python','Perl']
lst = wx.ListBox(panel, size=(100,-1), pos=(10,10), choices=languages, style=wx.LB_SINGLE)
frame.Bind(wx.EVT_LISTBOX, onListBox, lst)
frame.Show(True)
app.MainLoop()