$(document).ready(function(){
	$('#arrow_up').click(function() {
		var f = $('.home_cert div:first-child');
		$('.home_cert').append(f);
	});
	
	$('#arrow_down').click(function() {
		var newElm = $('.home_cert div:last-child');
		$('.home_cert').prepend(newElm);;
	});
})

	function f(id,def) {
		var cur = $('#'+id).val();
		if(cur == def){
			$('#'+id).val('');
		}
	}
	function g(id,def) {
		var cur = $('#'+id).val();
		if(cur == '') {
			$('#'+id).val(def);
		}
	}