HTTP Error 404.0 - Not Found

I'm using Errorhandler in my web application in vs 3.5
But when anyone enters www.myurl.com/abc  or www.myurl.com/wrongurl.htm or html
he got error
HTTP Error 404.0 - Not Found The resource you are looking for has been removed, had its name changed, or is temporarily unavailable. I googled on this bt found no good solutions rather I tried this
<customErrors mode ="RemoteOnly" defaultRedirect ="~/Errorpage.htm">
      <error statusCode ="404" redirect ="~/Errorpage.htm"/>
</customErrors>

still my problem is not getting sorted.
Can anyone help.


...