Global Exception handler

1.Apart from being a terrible user experience unhandled exceptions can also be a security problem. 
implement a global exception handler.To do this, open the Global.asax file
Add code to implement the Application_Error handler as follows.
void Application_Error(object sender, EventArgs e)
     {
     Exception myEx =  Server.GetLastError();
    String RedirectUrlString = "~/Error.aspx?InnerErr=" +
           myEx.InnerException.Message.ToString() + "&Err=" + myEx.Message.ToString();
     Response.Redirect(RedirectUrlString);
     }

2.Then add a page named Error.aspx to the solution and add this markup snippet.
<center>
  <div class="ContentHead">ERROR</div><br /><br />
  <asp:Label ID="Label_ErrorFrom" runat="server" Text="Label"></asp:Label><br /><br />
  <asp:Label ID="Label_ErrorMessage" runat="server" Text="Label"></asp:Label><br /><br /> </center>


3.Now in the Page_Load event handler extract the error messages from the Request Object.
protected void Page_Load(object sender, EventArgs e) {
    Label_ErrorFrom.Text = Request["Err"].ToString();
    Label_ErrorMessage.Text = Request["InnerErr"].ToString(); }