Spring MVC

1)In Spring MVC if we use @Controller,@RequestMapping,by default Dispatcher Servlet will call 
DefaultAnnotationHandlerMapping,but this handler mapping have no more features like
                        a)Validation Support.
                        b)Message Conversion.
                        c)Support For Field Formatting 
             To get all of the above feauters we have to add in .XML file this small annotation
 <mvc:annotation-driven/>

2)In ExtJs the Ajax Call will be happen like below,with form

Ext.Ajax.request({
})