Listing 7-4. exception.html
Listing 7-5. Output of exception.html in Firefox
Listing 7-6. Output of exception.html in Internet Explorer
Looking at the error messages, you can see that exceptions in Firefox are more useful for general debugging, but exceptions are still useful even without line properties because you end up knowing which block of code caused the error. They also allow you to handle the error programmatically, letting you give the user an error message or even perform a workaround instead of having your code silently break.