// 流程：检查是否投过，1.已投，alert提示，终止投;2.票没投就投，记录COOKIE；
function checkCookie(this_id){
	if(is_voted(this_id)){
		alert('您已经投过票');
	}
	else{
		ding(this_id);
		setcookie(this_id);
	}
}
function is_voted(this_id){
	var cookiearr=document.cookie.toString().split("; ");
	for (var i=0;i<cookiearr.length;i++){
		var cookiesubarr=cookiearr[i].split("=");
		if (cookiesubarr[0]==this_id){
		//alert(cookiesubarr[0]+"和它的值"+cookiesubarr[1]);
		return true;
		}
	}
	return false;
}

function setcookie(this_id){
var date=new Date();
var expireshours=12;//据估算应该是小时
date.setTime(date.getTime()+expireshours*3600*1000);
document.cookie=this_id+"=999; path=/; expires="+date.toGMTString();
}