Question

Im using forms authentication. I want my application should not logout the user automatically after sometime.

Answer 1

You can change the timeout like this:

<system.web>
    <authentication mode="Forms">
          <forms timeout="99999999"/>
    </authentication>
</system.web>

Further config options can be found here.

Make sure your session timeout isn’t less than the forms authentication timeout. Otherwise, your users will have a hard time using your site.

You can change the session timeout in the web.config:

<system.web> 
    <sessionState timeout="999999999" /> 
<system.web> 

Further details can be found here.

It could be a security issue to have someone logged in indefinitely.