if($('main_nav')){
lis = $('main_nav').select('li');
lis.each(function(li){
	var snav = li.down('.sub_nav');
	snav && Prototype.Browser.Gecko && snav.setStyle({width: snav.select('a').length * 80 + 'px'})
	snav && snav.setStyle({left: - (snav.getWidth() - li.getWidth()) / 2 + 'px'});
	li.observe('mouseover', function(){
		this.addClassName('current');	
		snav && snav.show();
	})
	li.observe('mouseout', function(){
		this.removeClassName('current');
		snav && snav.hide();
	})
})
}
if($('column_nav')){
	lis = $('column_nav').select('li');
	lis.each(function(li){
		var snav = li.down('.sub_nav');
		li.observe('mouseover', function(){
			this.addClassName('current');	
			snav && snav.show();
		})
		li.observe('mouseout', function(){
			this.removeClassName('current');
			snav && snav.hide();
		})
	})	
}