State Management :: Session Is Expire Error Processing Request / Config File Is Attache

i make a web site using frame but session is expire message is

Object reference not set to an instance of an object
Description: HTTP 500. Error processing request.

Stack Trace:

System.NullReferenceException: Object reference not set to an instance of an object at System.Web.UI.Control.OnLoad (System.EventArgs e) [0x00000] in <filename unknown>:0 at System.Web.UI.Control.LoadRecursive () [0x00000] in <filename unknown>:0 at System.Web.UI.Page.ProcessLoad () [0x00000] in <filename unknown>:0 at System.Web.UI.Page.ProcessPostData () [0x00000] in <filename unknown>:0 at System.Web.UI.Page.InternalProcessRequest () [0x00000] in <filename unknown>:0 at System.Web.UI.Page.ProcessRequest (System.Web.HttpContext context) [0x00000] in <filename unknown>:0 My Web Config file is<configuration> <!-- store the database connection info here --> <appSettings> <add key="sBook_StoreDBConnectionString" value="Provider=Microsoft.Jet.OLEDB.4.0;User ID=Admin;Data Source=C:Program FilesCodeChargeExamplesBookStoreBookStore_MSAccess.mdb;Persist Security Info=False" /> </appSettings> <system.web> <httpRuntime executionTimeout="1000" maxRequestLength="2000000" /> <!-- DYNAMIC DEBUG COMPILATION Set compilation debug="true" to enable ASPX debugging. Otherwise, setting this value to false will improve runtime performance of this application. Set compilation debug="true" to insert debugging symbols (.pdb information) into the compiled page. Because this creates a larger file that executes more slowly, you should set this value to true only when debugging and to false at all other times. For more information, refer to the documentation about debugging ASP.NET files. --> <compilation defaultLanguage="c#" debug="true" /> <!-- CUSTOM ERROR MESSAGES Set mode="on" or "remoteonly" to enable custom error messages, "off" to disable. Add <error> tags for each of the errors you want to handle. --> <customErrors mode="Off"/> <!--<customErrors mode="On" defaultRedirect="Login.aspx"> <error statusCode="500" redirect="Login.aspx"/> <error statusCode="404" redirect="Login.aspx"/> <error statusCode="403" redirect="Login.aspx"/></customErrors> --> <!-- AUTHENTICATION This section sets the authentication policies of the application. Possible modes are "Windows", "Forms", "Passport" and "None" --> <authentication mode="None" /> <!-- APPLICATION-LEVEL TRACE LOGGING Application-level tracing enables trace log output for every page within an application. Set trace enabled="true" to enable application trace logging. If pageOutput="true", the trace information will be displayed at the bottom of each page. Otherwise, you can view the application trace log by browsing the "trace.axd" page from your web application root. --> <trace enabled="false" requestLimit="10" pageOutput="false" traceMode="SortByTime" localOnly="true" /> <!-- SESSION STATE SETTINGS By default ASP .NET uses cookies to identify which requests belong to a particular session. If cookies are not available, a session can be tracked by adding a session identifier to the URL. To disable cookies, set sessionState cookieless="true". --> <sessionState mode="InProc" stateConnectionString="tcpip=localhost:42424" cookieless="false" timeout="60" /> <!-- GLOBALIZATION This section sets the globalization settings of the application. --> <globalization requestEncoding="utf-8" responseEncoding="utf-8" /> </system.web> <connectionStrings> <add name="mydb" connectionString="Server=localhost;User=SYSDBA;Password=datacenter;Database=/opt/db/erp2.fdb;Min Pool Size=5;Max Pool Size=60;Connect Timeout=30" providerName="FirebirdSql.Web.Providers" /> <add name="mydb2" connectionString="Server=localhost;User=blackberry;Password=acgmkRMS;Database=/opt/db/pwd.fdb;Min Pool Size=5;Max Pool Size=60;Connect Timeout=30" providerName="FirebirdSql.Web.Providers" /> </connectionStrings></configuration>