how to prevent browser back button

Question

hi friends I have login in my application.In every page I am checking Session[UserId] is null or not.If null I am redirecting to Login page.But when user clicks on browser back button it redirects to previous page and it giving object reference error. So how to prevent this when user clicks browser back button after logout it should display only login page. Thanks in advance

Krishna Rajput Singh · Answer

thank you for writing prasanna p below links helpful for you........:) http://www.dotnetfunda.com/forums/show/14280/prevent-browser-back-button-to-redirect-to-the-previous-page-in-aspnet http://stackoverflow.com/questions/12978285/prevent-back-button http://www.c-sharpcorner.com/blogs/disable-browser-back-button1

Midhun T P · Answer

Hi This error may be happening because you may be checking session is null as below - if(Session[username].ToString()!=) You should check session is empty like below- if(Convert.ToString(Session[username])!=) Also you should delete session value in logout button click using below code- Session.Abandon();

Dhananjay Kumar · Answer

page 1(default.aspx) Session [ id ] = TextBox1 . Text ; // just the username page 2 ( Default2 .aspx) in page load protected void Page_Load ( object sender EventArgs e) { Response . Cache . SetCacheability ( HttpCacheability . NoCache ); Response . Cache . SetExpires ( DateTime . Now . AddDays (- 1 )); Response . Cache . SetNoStore (); if ( Session [ id ] == null ) { Response . Redirect ( Default.aspx ); // redirects to page1(default.aspx) } else { Label1 . Text = ( string ) Session [ id ]; //just display user name in label } } In page 2 log out button protected void Button1_Click ( object sender  EventArgs e ) { Session [ id ] = null ; Response . Redirect ( /WebSite5/Default.aspx ); //redirects to page1(default.aspx) } http://stackoverflow.com/questions/21930487/how-to-prevent-browser-back-button-after-logout