More information about the onMessage search feature can be found in this Help Topic

To adjust search settings, go to onMessage:
  • Select Settings > Search
You can then click Add under Featured Links to add a new link or select Search History to view what users have been searching for

To add a search to an onMessage page:
  1. Select Website > Main Site
  2. Select Master Layouts
  3. Choose a layout
  4. Under widgets on the left, find Search
  5. Drag the widget onto the layout
  6. Click Apply Changes