The correct event to use, which guarantees that MS AJAX controls on the page are created (and the Prometheus controls are built on top of MS AJAX) is the Sys.Application.add_init
If you examine the generated page source where MS AJAX controls are present in the page bottom you will see that they are created during this event as well - and the event itself is fired after the window.onload
Thus the following code should work:
var tooltip = $find("<%= this.RadToolTip1.ID %>");
(which you probably already do).
On a side note, in the coming Q1
we do plan to extend the tooltip and provide serverside methods such as Show
, similar to the ModalPopupExtender control available in the MS AjaxControlToolkit.
the Telerik team