setting the height of line box

Element like span is inline element. Their horizontal spacing can be adjusted using horizontal padding, border, and margin. However, vertical pading, border, margins will have no effect on the height of an line box.But you can use line-height to change the height of this box.

Sys.UI.Control

Conceptually, a control differs from a behavior in the sense that instead of just providing client functionality, a control usually represents or wraps the element, to provide additional properties and methods that extend its programming interface.

Sys.UI.Behavior

            Type.registerNamespace('Samples');
            Samples.EmptyBehavior = function(element) {
            Samples.EmptyBehavior.initializeBase(this, [element]);
            }
            Samples.EmptyBehavior.prototype = {
            initialize : function() {
            Samples.EmptyBehavior.callBaseMethod(this, 'initialize');
            },
            dispose : function() {
            Samples.EmptyBehavior.callBaseMethod(this, 'dispose');
            }
            }
            Samples.EmptyBehavior.registerClass('Samples.EmptyBehavior',
            Sys.UI.Behavior);

expose event in asp.net ajax

1. Create a method that adds an event handler.
2. Create a method that removes an event handler.
3. Create a method that is responsible for raising the event.

cancel request vs abort reqeust

In asp.net ajax framework, you can cancel request before the request is submitted to the server, you can aborted the request after the request is submitted to the server and before the response is received.