var all_with_submenu = $('nav').getChildren().getChildren().flatten().map(function(i){ 
		if((i.getChildren('ul').length)>=1){ 
			return i;
		}
	}).flatten();
		
	// Add behavior  mouseover and mouseleave 
	all_with_submenu.each(function(i){
		i.getChildren('ul')[0].setStyle('display','none');


		i.addEvent('mouseover', function(event){
				var coordinates = this.getChildren('a')[0].getCoordinates(document);
			if(event.page.x > coordinates.left && event.page.x < coordinates.right && event.page.y > coordinates.top && event.page.y < coordinates.height){
				this.getChildren('ul')[0].setStyle('top', (coordinates.height - 20) );
				this.getChildren('ul')[0].setStyle('left', '20px' );
				this.getChildren('ul')[0].setStyle('display', 'block');
				}
		});
			i.addEvent('mouseleave', function(){
				this.getChildren('ul').setStyle('display', 'none');
				}
			);
		});
		// Main Nav behavior
		
		// behavior for tabs  <-- to be optimized //
window.addEvent('domready', function() {

	
});