NumericUpDown Extender Control in Ajax

The NumericUpDown Extender is an ASP.NET AJAX extender that can be attached to an ASP.NET TextBox control to add "up" and "down" buttons that increment and decrement the value in the TextBox. The increment and decrement can be simple +1/-1 arithmetic; they can cycle through a provided list of values.
Refer this link
http://www.asp.net/ajaxlibrary/AjaxControlToolkitSampleSite/NumericUpDown/NumericUpDown.aspx