jquery交替实现隐藏、显示

<html>
<head>
<title></title>
</head>
<script src="jquery2.1.min.js"></script>
<script type="text/javascript" >
function test(){
var css=$("div").css("display");
if(css=="block"){
$("div").hide();
}else if(css=="none"){
$("div").show();
}
}
</script>
<body>
<div>看这里。。。</div>
<input type="button" value="测试" onclick="test()"/>
</body>
</html>

/**

* Created by yangming on 2015/8/6.

*/

function change_bill_detail(detail_id) {

var css=$("#" + detail_id).css("display");

if(css=="block"){

$("#icon-"+detail_id).removeClass("glyphicon glyphicon-triangle-top").addClass("glyphicon glyphicon-triangle-bottom");

$("#"+detail_id).hide();

}else if(css=="none"){

$("#icon-"+detail_id).removeClass("glyphicon glyphicon-triangle-bottom").addClass("glyphicon glyphicon-triangle-top");

$("#"+detail_id).show();

}

}