Example of how to find the target/toElement localName

firefox.toElement.js

var t = false; // Default.

// Get the right target being clicked.
if ( 'target' in event ) {
	t = event.target.localName; // Gecko
} else if ( 'toElement' in event && 'undefined' !== event.toElement ) {
	t = event.toElement.localName; // Webkit
}

// If the target is an img, a, or li, it's a safe item in the menu.
if ( 'a' != t && 'li' != t && 'img' != t ) {
	// Do my things as long as they are not these elements.
}