Checking for the presence of a webapp

[joer.banno]

Hi,

In a webapp I'm writing I need to know if another webapp is running
(both of which are asp.net), is there a way that you can check for the
presence of another webapp?

The problem is that my first webapp sends an invite to users to visit
another webapp, this second webapp can be published in any kind of url
or domain.

So I want to protect my users (of the first webapp) by checking the
presence of the second website app, before being able to send the
invitation.

 

[joer.banno]

http://www.codeguru.com/csharp/.net/net_asp/miscellaneous/article.php...

Thank you very much,
My first thought was to consider writing a webservice, that is part of
the referred to webapp, only to realize that it would leave me with
the same problem for the webservice.