Method call from javascript

I would like to call a method from client side javascript.

By using AjaxFramework of microsoft we can call sever side web method from javascript

Ex:

PageMethods.GetOptions(param1,OncallOptionCompleted,OncallOption Error);

above

[B]Get Option[/B] is Server side method declare as Public Webmethod in code behind file

param1- parameter to funtion

OncallOptionCompleted - after call server side method we will get value from this method
OncallOption Error - this one call if any error occur in the server method

I hope this one was clear to you