ericmbarnard/Knockout-Validation — pull request #92 by TerenceLewis (2012-07-10 10:26:50+00:00)
Title: Fix for issue #82

Hi @ericmbarnard,

Calling utils.isValidatable, coming from line 639:
```javascript
if (config.insertMessages && utils.isValidatable(valueAccessor())) {
```

In some cases in my app (for more complicated screens) valueAccessor() is sometimes undefined, so I've added a small check to first make sure there is a valid extended observable before calling
```javascript
o.rules && o.isValid && o.isModified;
```