当用户检查一个类别并键入一个项目并点击添加到列表按钮时 item被添加到列表文本框中，当用户以任何顺序输入项目时，他们可以使用Print Sorted List按钮创建所有添加的杂货的排序列表。感谢
<title>Grocery List</title>
<script language="JavaScript">
<!-- HIDE FROM INCOMPATIBLE BROWSERS
function addItem() {
//To add a variable to an object value:
var x = y + ' > ' + document.MyForm.item.value;
//To add an option to a listbox:
addListItem = new Option(x,x);
document.MyForm.list.options[i++] = addListItem;
}
function printSortedList() {
//To determine which radio button has been selected:
for (var i=0; i < document.MyForm.category.length; i++)
{
if (document.MyForm.category[i].checked)
{
var y = MyForm.category[i].value;
}
}
}
// STOP HIDING FROM INCOMPATIBLE BROWSERS-->
</script>
</head>
<body>
<form name="groceryList">
Category: <input type="radio" name="category" value="Produce">Produce</input>
<input type="radio" name="category" value="Meat and Cheese">Meat and Cheese</input>
<input type="radio" name="category" value="Grocery">Grocery</input>
<input type="radio" name="category" value="Beverage">Beverage</input>
<br />
Item: <input type="text" length="30" name="item" />
<p />
<input type="button" name="add" value="Add to List" onClick="addItem()"/>
<p />
<select name="list" size="10" style="width:500"></select>
<p />
<input type="button" name="sort" value="Print Sortedlist"onClick="printSortedList()"/>
</form>
</body>
</html>