Hello Chinna,
By assigning the
OnClientBeforeShow property to a function you actually attach a handler for this event and you do not need to pass the function's arguments explicitly - they are automatically passed. This could not be the reason for the error you got.
I did not quite understand what you mean by
"when i kept Mouse position at the bottom of the Aspx page it has to show the tooltip at the bottom of the Mouse position by scrolling the page down". I think that the best way to proceed is that you open a new support ticket, prepare and send me a fully working, reproduction demo (including DB, if needed, e.g Northwind) along with a detailed explanation of the problem and the desired behavior and some screenshots. Once I receive this information, I will do my best to help.
Regards,
Svetlina
the Telerik team
Check out
Telerik Trainer, the state of the art learning tool for Telerik products.