Browser handling of broken includes in an Ajax world?

In this mordern web 2.0 age, javascript includes are used more and more – and in some cases solutions often depend on included content from 3rd parties. While it is nice these 3rd parties may provide us with data (such as the latest tweets from twitter), it would be quite nice, if issues on their server didn’t break the fancy page we’re building.

So the question is this: If you build a page and include javascript from foreign scripts, will error messages on their part break your site? We’ve made the assumption, that the Web2.0 page will degrade gracefully, so that the content/functionality of the javascript-includes is just extra frosting, not needed to use the page

We did a simple little test, and in the most common browsers, a server error (that is an errror signaled in the http-header status code), will just cause the browser to ignore the included content. If the header is a “200 Ok” header, the content will break.

The answer, no – assuming, that their servers provides a http-header, that signals error. If you have a few spare seconds, please visit the test page, and if your browser reports a javascript error, please leave you browser (make and model) and operating system in a comment below.