各位大侠，下面代码<select>标签中的onChange函数为何没响应

<html><head>
<script type = "text/javascript">
var phone_book = new Array();
phone_book["birney"] = "234343255";
phone_book["sturm"]  = "234394390";
phone_book["vixtel"] = "343048302";
pbone_book["jerry"]  = "8084032840"
pbone_book["benson"] = "80899348320";
function displayNumber( phone_book, entry )
{
alert( "hello" );
//document.write( "<h1>Hey you Guys!</h1>" );
//var theNumber = phone_book[entry];
//window.document.the_form.number_box.value = theNumber;
}
</script>
</head>
<body>
    <form name = "the_form">
     <b>Name:</b>
        <select onChange = "displayNumber( phone_book, this.options[SelectedIndex].value );">
         <option value = "birney">Birney
            <option value = "strum" >Sturm
            <option value = "vixtel">Vixtel
            <option value = "jerry" >Jerry
            <option value = "benson">Benson
        </select>
        <p>
     <b>Number:</b>
        <input type = "text" name = "number_box" value = ""/>
    </form>
</body></html>

解决方案 »

  1.   

    <html><head>
    <script type = "text/javascript">
    var phone_book = new Array();
    phone_book["birney"] = "234343255";
    phone_book["sturm"] = "234394390";
    phone_book["vixtel"] = "343048302";
    phone_book["jerry"] = "8084032840"
    phone_book["benson"] = "80899348320";
    function displayNumber( phone_book, entry )
    {
    alert( "hello" );
    //document.write( "<h1>Hey you Guys!</h1>" );
    //var theNumber = phone_book[entry];
    //window.document.the_form.number_box.value = theNumber;
    }
    </script>
    </head>
    <body>
      <form name = "the_form">
      <b>Name:</b>
      <select onChange = "displayNumber( phone_book, this.options[selectedIndex].value );">
      <option value = "birney">Birney
      <option value = "strum" >Sturm
      <option value = "vixtel">Vixtel
      <option value = "jerry" >Jerry
      <option value = "benson">Benson
      </select>
      <p>
      <b>Number:</b>
      <input type = "text" name = "number_box" value = ""/>
      </form>
    </body></html>
      

  2.   

    selectedIndex前面要不要加个this啊
      

  3.   


    <html>
    <head>
    <script type = "text/javascript">
    var phone_book = new Array();
    phone_book["birney"] = "234343255";
    phone_book["strum"] = "234394390";
    phone_book["vixtel"] = "343048302";
    phone_book["jerry"] = "8084032840"
    phone_book["benson"] = "80899348320";
    function displayNumber(entry)
    {
    var theNumber = phone_book[entry.value];
    window.document.the_form.number_box.value = theNumber;    
    }
    </script>
    </head>
    <body>
      <form name = "the_form">
      <b>Name:</b>
      <select onChange = "displayNumber(this);">
      <option value = "birney">Birney
      <option value = "strum" >Sturm
      <option value = "vixtel">Vixtel
      <option value = "jerry" >Jerry
      <option value = "benson">Benson
      </select>
      <p>
      <b>Number:</b>
      <input type = "text" name = "number_box" value = ""/>
      </form>
    </body>
    </html>