// The client event ThumbMouseDown takes two parameters sender and e
// sender is the object which is raising the event
// e is the SliderThumbMouseEventArgs
function WebSlider1_ThumbMouseDown(sender, e) {
var slider = $find("WebSlider1");
//Checks which thumb is involved in the event
//True means secondary thumb and false means main thumb
var thumb = e.isSecondary();
if (thumb == true) {
//Gets value at the secondary thumb
var secondaryValue = slider.get_secondaryValue();
}
else {
//Gets value at the main thumb
var mainValue = slider.get_value();
}
}