Event.observe(window, 'load', function(){
	var menu = $$('#main_menu ul')[0];
	if(menu.childNodes){
		Element.cleanWhitespace(menu);
		var dim = Element.getDimensions(menu);
		var childNum = menu.childNodes.length;
		var childWidth = Math.floor(dim.width/childNum);
		var marginLeft, marginRight;
		$A($R(0, (childNum-1))).each(function(u){
			marginLeft = parseInt(Element.getStyle(menu.childNodes[u], 'marginLeft'));
			marginRight = parseInt(Element.getStyle(menu.childNodes[u], 'marginRight'));
			marginLeft = isNaN(marginLeft)?0:marginLeft;
			marginRight = isNaN(marginRight)?0:marginRight;
			Element.setStyle(menu.childNodes[u], {width: (childWidth-marginRight-marginLeft)+'px'});
		});
	}
});