Clearing the selection in GTK_COMBO_BOX?

["Leon Ross" <subaruwrx88011 gmail com>]

I am building an app to simulate sending messages to different processes. In
this app I will select a message (via a GTK_COMBO_BOX) which
will display editable  fields in the message. After editing the fields I
will then push a button to send the message. After I do that I would like
the GTK_COMBO_BOX not to be displaying the message that was sent, I would
like it to be clear. I understand how to do this with GTK_COMBO but is there
any way to do using GTK_COMBO_BOX?

Thanks
Leon