sstephenson/prototype — pull request #89 by jwestbrook (2012-12-28 21:47:44+00:00)
Title: fix for IE8 opacity check

check if `match` exists before checking if `match[1]` exists

IE8 fails to set the `match` variable which throws a javascript error that

```
'1' is null or not an object.
```
Check before `match` is used to prevent that from happening.

This was discovered by using script.aculo.us and running the `appear()` method on a div element. IE8 errored but other browsers did not.