I have been trying to set up a custom error message for two days and to no avail.

I am somewhat new to DNN and website creation in general, but it is my job now and I really want to be able to show that I can do it.   

I've created an error page on the site and the web.config to that, that didn't work.  Then I edited the ErrorPage.aspx and tried to set the web.config to that... also didn't work.  My web.config error section currently reads:  

<!-- permits errors to be displayed for remote clients -->
    <customErrors mode="On"> defaultRedirect="Errorpage.aspx"> 
  </customErrors>

I also tried to go into the server and change the web.config file custom errors section to direct the 404b errors to the ErrorPage.aspx file, but that didn't work either.  It seems everything I have found online regarding this is for a previous version of DNN.  Can anyone help?  Please? 

Thanks.