Iframes are a bit tricky. Ordinarily your code might work in IE. However, for all other browsers, the script engine will never retrieve an element by id if it doesn't have that id. In your example you are getting the iframe by id but it is its name, not its id that is set to 'info'. Additionally, as I say, iframes are tricky so even though IE will often retrieve a named element by id, even it probably won't in this case. To make matters worse, iframes don't usually respond well to having their src attribute changed in this fashion. A better approach would be:
This will access the iframe by name and load the new address into it.