// The client event TickmarkLabelMouseDown takes two parameters sender and e
// sender is the object which is raising the event
// e is the SliderTickmarkMouseEventArgs
function WebSlider1_TickmarkLabelMouseDown(sender, e) {
var slider = $find("WebSlider1");
//Checks if control is enabled or disabled
var check = slider.get_enabled();
//Gets main value as object
var value = slider.get_value();
//Gets percent between edge of track bar(working area) and a tickmark label which is closest to location of mouse
var resultVar = e.get_tickPercent();
}