Doubt regarding Exception handling in Watir

[Simbolla Simbolla]

Hi all,

below is my code
def gotourl(url)
begin
$ie.goto(url)
rescue Watir::Exception::NavigationException => e
puts "navigation error"
printscreen(url)
end
end

1.in IE 8.0 version i get this error message when i navigate to invalid
URL "Internet Explorer cannot display the webpage"

my doubt is why rescue part is not executing for this error.

2.i want to know is it possible to use only "Watir::Exception" in my
rescue portion some thing this like this.

def gotourl(url)
begin
$ie.goto(url)
rescue Watir::Exception => e
puts "navigation error"
printscreen(url)
end
end

def clickbutton()
begin
$ie.buttonname,'btnGs').flash
rescue Watir::Exception => e # instead of
Watir::Exception::UnknownObjectException
puts "object not found error"
printscreen($ie.title)
end
end

3. What is the best of Exception handling in watir?
Please some body give me the best approach to do Exception handling
in watir