express save function in javascript and ajax codes

Question

 I going to be studing Asp.net web developemnt,, i know ajax used for avoiding pagereloading..

I want  example code just save function on btnsaveclick,,,

This code express  how to save using javasript and ajax...

that is

save using javaScript 

please write code here

save using ajax 

please write  code here

By this i can study programmaticallyy

pls helpme......