The OnClientSlideRangeStart client-side event occurs just before the user starts sliding the selected region of RadSlider, thus changing both SelectionStart and SelectionEnd values. The properties EnableDragRange and IsSelectionRangeEnabled of RadSlider should be set to true in order to enable the sliding region of the control.
The event handler receives two parameters:
The slider instance that fired the event.
Event arguments. The parameter has no methods for this event.