JavaScript实现级联菜单的方法

本文实例讲述了JavaScript实现级联菜单的方法。分享给大家供大家参考。具体实现方法如下：

<html>

<head>

<title>test</title>

<script type="text/javascript">

function f()

{

var sel=document.getElementById("country");

var sel2=document.getElementById("city");

var cnarr1=new Array("bj","sh")

var cnarr2=new Array("beijing","shanghai")

var usaarr1=new Array("dc","ny")

var usaarr2=new Array("Washington","NewYork")

for(var i=sel2.length;i>=0;i--){

sel2.removeChild(sel2.childNodes[i]);

}

var op=document.createElement("option");

op.value="please";

op.text="please";

sel2.appendChild(op);

if(sel.value=='USA'){

for(i=0;i<2;i++){

op.value=usaarr1[i];

op.text=usaarr2[i];

sel2.appendChild(op);

}

}

else if(sel.value=='CN'){

for(i=0;i<2;i++){

op.value=cnarr1[i];

op.text=cnarr2[i];

sel2.appendChild(op);

}

}

}

</script>

</head>

<body>

<select onchange="f()" id='country'>

<option >please</option>

<option value='USA'>America</option>

<option value='CN'>China</option>

</select>

<select id='city'>

<option >please</option>

</select>

</body>

</html>

希望本文所述对大家的javascript程序设计有所帮助。