Please Help Me About Web View

I use a website address in my web view, but some time the site is down, this time Web view show massage ""This site in unreachable like this. but i want when my site is down or provide address r not working then i give custom massage , i don’t want to show my website name when is’t down.

Please help how can i do this

I believe you can’t do anything about it, because it returns a site and not a 404 error

does this page which is displayed have a special url or page title?
if yes you could use the webviewer properties CurrentPageTitle or CurrentUrl to find out, if that webpage is down