WPF Editable ComboBox styling

I have a small question开发者_C百科: How do i style a WPF ComboBox with property IsEditable=True. I used Blend to extract the default template.

Now i see a style ComboBoxEditableTextBox i've managed to set the borderbrush on default state but how can i set the border when i'm editing (focus on the textbox)?

Did u try setting the BorderThickness upon (IsFocused = True and IsReadOnly = False) multi-triggers