How to put Asp.net site under maintainence

Placed Live Asp.net site under maintainence or monitering
Firstly create App_Offline.htm file in the root of your asp.net website.Define your markup for the end user to display in this file when your live website is under maintainence or monitering session.Now,whenever you view any of your website page it will show code on your App_Offline.htm file.

After ajaxify the pages gridview rowcommand event not firing on page refresh

Problem:
I have an .aspx where i am loading gridview data for the first time using (!ispostback).On the same page i have a linkbutton which fires a Modelpopup extender which has a target id of panel which includes two textbox,one file upload and two button controls.In the gridview i have two button column for edit and delete.But when i load the page for the first time,gridview rowcommand is not firing.
1)So,how should i wrap the code in order to fire the gridview rowcommand events.
2)In the panel i have two button controls and none of there click is binding to the code behind.so how to fire these two controls events.
Please mention your valuable comments and help me out.