<%@ Page Language="C#" %> <%@ Import Namespace="System.Web.Configuration" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> void Page_Load() { if (!Page.IsPostBack) { Configuration config = WebConfigurationManager.OpenWebConfiguration (Request.ApplicationPath); CompilationSection section = (CompilationSection)config.GetSection ("system.web/compilation"); chkDebug.Checked = section.Debug; } } protected void btnUpdate_Click(object sender, EventArgs e) { Configuration config = WebConfigurationManager.OpenWebConfiguration (Request.ApplicationPath); CompilationSection section = (CompilationSection)config.GetSection ("system.web/compilation"); section.Debug = chkDebug.Checked; config.Save(ConfigurationSaveMode.Modified); } </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> <title>Show Config Modify</title> </head> <body> <form id="form1" runat="server"> <div> <asp:CheckBox id="chkDebug" Text="Enable Debugging?" Runat="server" /> <br /><br /> <asp:Button id="btnUpdate" Text="Update" OnClick="btnUpdate_Click" Runat="server" /> </div> </form> </body> </html> File: Web.Config <configuration> <system.web> <compilation debug="true" /> </system.web> </configuration>