Cannot tell when a web page is not present

Using Firefox there is a new page that is sometimes displayed during my testing. When it is present there are no problems. When it is not I need to click a link to display the page.

The problem is that I get an error when the page is not there even though I am using the .Exists check in an if statement.

Reference the code that follows:

When the page https://somepage.com/* is present this has no problem. It falls right past the if statement correctly. However when the page is not present I get the error "The page 'https://somepage.com/*' was not found." instead of it going into the if statement and doing the click action.

CODE:

function AddSomething() {

  var browser = Sys.Browser("*");
 
  if( browser["Page"]("https://somepage.com/*")["Exists"] == false)
  {
    Aliases["MyLink"]["Click"]();
  }

  var Mypage = browser.Page("https://someplace.com/*");
 
  Mypage .Wait();

  do stuff ....

}