How to make the browser navigate to my URL?

Hi, 

I'm trying to make my browser navigate to a URL.

I've tried the following code:

Sys.Browser("iexplore").ToUrl("www.google.com");

and also 

Sys.Browser("iexplore").Navigate("www.google.com");

but my test fails:

Unable to find the object Sys.Browser("iexplore"). 

The object does not exist. 

Can anyone help?