求各位指点下这段代码是什么意思
<script type="text/javascript">
function setTab(name, cursel, n) {
for (i = 1; i <= n; i++) {
var menu = document.getElementById(name + i);
var con = document.getElementById("con_" + name + "_" + i);
menu.className = i == cursel ? "hover" : "";
con.style.display = i == cursel ? "block" : "none";
}
}
</script>
</head>
<body>
<div class="z_main">
<ul class="tab_m">
<li id="qi1" onclick="setTab('qi',1,5)">1</li>
<li id="qi2" onclick="setTab('qi',2,5)">2</li>
<li id="qi3" onclick="setTab('qi',3,5)">3</li>
<li id="qi4" onclick="setTab('qi',4,5)">4</li>
<li id="qi5" onclick="setTab('qi',5,5)">5</li>
</ul>
<div class="tab_box" id="con_qi_1">1</div>
<div class="tab_box" id="con_qi_2">2
</div>
<div class="tab_box" id="con_qi_3">3</div>
<div class="tab_box" id="con_qi_4">4</div>
<div class="tab_box" id="con_qi_5">5</div>
<script>setTab('qi', 1, 5)</script>
</div>
</body>
看别人在html中写的 但有点不是太懂 请各位指点一下