def on_lstClassifications_itemSelectionChanged(self):
        """Update classification description label and unlock the Next button.

        .. note:: This is an automatic Qt slot
           executed when the field selection changes.
        """
        self.clear_further_steps()
        classification = self.selected_classification()
        # Exit if no selection
        if not classification:
            return
        # Set description label
        self.lblDescribeClassification.setText(classification["description"])
        # Enable the next button
        self.parent.pbnNext.setEnabled(True)