There are two way to set session timeout
property in ASP.Net.
First
Go to web.config file and add following
script.
<configuration>
<system.web>
<sessionState
mode="InProc"
cookieless="true"timeout="60"/>
</sessionState>
</system.web>
</configuration>
Second
Go to global.asax file and write the code
below:
void
Session_Start(object sender, EventArgs e)
{
Session.Timeout = 60;
}