i have a .config file.in taht i have two key and value.

 <appSettings>
    <add key ="ConnectionString" value= "Data Sourrce=Clint2;Initialcatalog=FAMS;UID=sa;PWD=sa123"/>
    <add key="CommandTimeout" value="500"/>
  </appSettings>
i m accessing it from a class

Private connectionString As String = System.Configuration.ConfigurationSettings.AppSettings("ConnectionString")

Here is the answer to your problem: http://www.geekpedia.com/Question34_In-.NET-2.0-accessing-the-values-stored-in-web.config-through-System.Configuration.ConfigurationSettings.AppSettings-doesnt-seem-to-work-anymore.html