代码运行不正常，急

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>JScript exercise(9)</title></head><body><form name="the_form">
<b>Name:</b>
<select onChange="displayNumber(phone_book,this.value)">
<option value="happy">Happy</option>
<option value="sleepy">Sleepy</option>
<option value="sneezy">Sneezy</option>
<option value="sleazy">Sleazy</option>
<option value="sneery">Sneery</option>
<option value="bleary">Bleary</option>
<option value="tweaked">Tweaked</option>
</select>
<p>
<b>Number:</b>
<input type="text" name="number_box" value="">
</form>
<script language="JavaScript">
var phone_book=new Array();
phone_book["happy"]="(203)555-1234";
phone_book["sleepy"]="(203)555-2345";
phone_book["sneezy"]="(203)555-4321";
phone_book["sleazy"]="(203)555-3245";
phone_book["sneery"]="(203)555-3213";
phone_book["bleary"]="(203)555-2365";
phone_book["tweaked"]="(203)555-1664";
function displayNumber(phone_book,entry)
{
var the_number=phone_book[entry];
window.document.the_form.number_box.value=the_number;
}
</script>
</body>
</html>