DOMAttrModified not getting triggered

I am looking for attribute modifications by attaching a listener to the 
DOMAttrModified event for the document. However, this seems to get 
triggered only when I use the string method "setAttribute" to modify an 
attribute, for example myNode.setAttribute('value', 'yy'). It does not 
get triggered when I use the expando dot notation to modify an 
attribute, say myNode.value = 'yy'.

Is there something that I am doing wrong ?

Is there any event that I can listen for to changes in the DOM 
attributes using the expando dot notation ?

Thanks.