give error if page is not exist

Hi.
i use asp.net mvc, and i try unit tests and behviour driven development tests.
i want to give error if a page doesn't exist.
For example, i use this code:
selenium.Navigate().GoToUrl(baseurl+"/Index");

i also deleted Index view. That is, no view/page at the "baseurl+"/Index" route.
In fact, there is no ındex page, bu my test gives success.
Thanks in advance.

Can you assert on the basis of content of page

i can't understand what you said. Wht is the the basis of content of page.
i can't understand this?
Thanks.

Assert the absence of certain element /text on page