$(document).ready(function() {
	$(".arrow-table tr.even").hide();
	$(".arrow-table tr.odd td.first").click(
		function () {
			var TrTag = $(this).parent();
			var nextTr = TrTag.next();
			if($(this).hasClass('arrow-up')) {
				nextTr.hide();
			} else {
				nextTr.show();
			}	
			$(this).toggleClass('arrow-up');
		}
    ); 
});