Access to the Main Form DOM from Relationship Method

In ARAS 10.0, what is the appropriate way to access the DOM of the main Form from a Relationship Grid event? 

Here is the gist of the situation: I have a method (Javascript), that is a Relationship Grid event, and in that event, I want to access some HTML elements on the main form.  

In previous versions of ARAS, I was able to get to this via :  

parent.parent.frames[1].document; //form document object 

However, in 10.0 ...this doesn't work at all  :( 

Thanks in advance for any advice!