function vote() {
	var items = document.getElementsByName("item");
	if (items.length == 0) {
		alert("请选择投票选项!");
		return;
	}
	var itemArray = [];
	for (var i = 0; i < items.length; i++) {
		var item = items[i];
		if (item.checked) {
			var str = "item=" + item.value;
			itemArray.push(str);
		}
	}
	var option = {
		method: "post",
		postBody: itemArray.join("&"),
		onSuccess: function(xmlhttp) {
			alert(xmlhttp.responseText);
		},
		onFailure: function() {
			alert("投票出错");
		}
	}
	new Ajax.Request("vote.page", option);
}