As for allowing the slider value only to be incremented, you can use the OnClientValueChanging event for this purpose: http://www.telerik.com/help/aspnet-ajax/slider-client-side-onclientvaluechanging.html. First, you can compare the results of the get_oldValue and the get_newValue method of the event arguments parameter. If the old value is greater than the new value of the slider (the value is decreased), you can call set_cancel(true) similarly to the example in the help article and the value of the slider will not change.