var myrules = {
	'a.external' : function(el){
		el.onclick = function(){ 

			//alert('_blank');
			var newwin = window.open(this.href);
			return !newwin; 
			   
		};
		
	},
	'a.top' : function(el){
		el.onclick = function(){ 

			parent.location.href = this.href;
			//alert('_top');
		   
		};
		
	}	
	
};

Behaviour.register(myrules);