Why does my page error method not trigger here ?

Hi;
I am testing a custom error page for my web application.
To test the custom error page I commented out my database connection string in my config file.
This causes  my main page to crash when I try and store my now nonexistant connection string in that pages code behind.
I have a page_error handler on the page which points to a custom error page, but this never gets called ?
The connection string variable is declared at the top of the page.
Partial Class accountManager Inherits System.Web.UI.Page Private strConn As String = WebConfigurationManager.ConnectionStrings("CurrentAccounts_DevConnectionString").ConnectionString So why wouldn't the page_error be called when an error is encountered ?
Even outside the page's events you are still in the pages scope ?
Thanks for your insights !
 
 
...