Does anyone know of a way of getting TinyMCE working in the popup DOM window. I am using HTMLEditorField which is just displaying a standard textarea with no toolbar.

Thanks

Use SimpleWysiwygField. http://doc.silverstripe.org/doku.php?id=simplewysiwygfield

Thank you - but I could do with a little more help with integration of this into my existing code. This field is to replace the existing TextAreaField - Description:

<?php
class InfoBox extends DataObject
{
static $db = array (
'Title' => 'Text',
'Description' => 'Text',
'Link' => 'Text'
);

static $has_one = array (
'HomePage' => 'HomePage',
'MultiBox' => 'MultiBox',
'DropDown' => 'DropDown',
'Image' => 'Image'
);

public function getCMSFields_forPopup()
{
return new FieldSet(
new TextField('Title'),
new TextAreaField('Description'),
new TextField('Link'),
new ImageField('Image')
);
}

}
?>

There's an example right in the documentation I sent you. It should be as easy as replacing TextareaField with SImpleWysiwygField, and you can customize from there if you want.

I did try this but got the error message: Fatal error: Class 'SimpleWysiwygField' not found

When did you last run an update? It's been in the package for a while now.