SilverStripe 2.4.7

Hi

I'm looking for a way to validate the fields in my DOM popup. I need to, firstly, ensure that they have all been filled in. Next I need to make sure they are correct using Regular Expressions or something. I am ok with the regex but how do I go about applying validation to the fields?

Thanks

I've been trying to implement what these posts talk about but it has no effect.

http://www.silverstripe.org/data-model-questions/show/6128
http://www.silverstripe.org/customising-the-cms/show/8236

Even basic validation using the following does nothing.

 public function getCMSValidator() { 
      	return new RequiredFields(array('Title', 'Expires', 'Photo', 'Description', 'Weight', 'Price', 'Savings', 'Code')); 
  	}

When I try to add a new popup class I get this error

Class 'MyDataObjectManager_Popup' not found in /Applications/MAMP/htdocs/Gala/Gala/trunk/cms/sapphire/forms/ComplexTableField.php on line 600 

I'm using

 MyDOM->popupClass = 'MyDataObjectManager_Popup';