title: How to display a combobox based on a selection from another combobox
body: <p>I'm trying to display (enabled) a combobox based on a particular item selected in a previous combobox. I have attempted many combinations, and can't seem to get it to behave properly. It will display normally (disabled), but I want it only to display (enabled) when a certain item is selected. I've tried .Refresh() and EVT_COMBOBOX, and they do not work. Below is the code in question:</p>
  
  <pre><code>    #Media Quality
      self.formats3 = ['-sameq','-qmax']
      self.format_combo3=wx.ComboBox(self, size=(100, -1),value='Select Quality', choices=self.formats3, style=wx.CB_DROPDOWN, pos=(300,141))
      quality=self.format_combo3.GetValue()
  
  
      #-qmax settings
      self.formats4 = ['1','2','3','4','5','6','7','8']
      self.format_combo4=wx.ComboBox(self, size=(30, -1),value='0', choices=self.formats4, style=wx.CB_DROPDOWN, pos=(405,141))
      self.format_combo4.Disable()
  
      if quality == '-qmax':
          self.format_combo4.Enable()
  
      else:
          self.format_combo4.Disable()
  </code></pre>
  
  <p>Solution:</p>
  
  <pre><code>    #-qmax settings
      self.formats4 = ['1','2','3','4','5','6','7','8']
      self.format_combo4=wx.ComboBox(panel, size=(30, -1),value='0', choices=self.formats4, style=wx.CB_DROPDOWN, pos=(405,111))
      self.format_combo4.Disable()
  
  
      #Media Quality
      self.formats5 = ['Select Preset','video to mp3']
      self.format_combo5=wx.ComboBox(panel, size=(100, -1),value='Select Preset', choices=self.formats5, style=wx.CB_DROPDOWN, pos=(300,141))
  
      #Bit rate
      self.formats6 = ['k/bs','128000', '160000', '180000', '192000']
      self.format_combo6=wx.ComboBox(panel, size=(47, -1),value='k/bs', choices=self.formats6, style=wx.CB_DROPDOWN, pos=(405,141))
      self.format_combo6.Disable()
  
  
  
  
  def OncomboBox(self, e):
      quality=self.format_combo3.GetValue()
      if quality == '-qmax':
          self.format_combo4.Enable()
  
      else:
          self.format_combo4.Disable()
  </code></pre>