Unfortunately, there is no direct way to do it.
But you can work around this.
For example, save value of marker.label (tooltip) to marker.customData and remove the marker.label to hide the tooltip. Set the marker.label again (from marker.customData), when you need it.
http://infinity-code.com/doxygen/online … a199f29dc1

   I use OnlineMaps.instance.AddMarker to add my markers on map.

   There's a simple way to show/hide via script the tooltip of a specified marker?

   Thank you!

   Gius