用Ajax将checkbox选中的值发送给后台

献上代码

var postInstall=function(data,fn){                           //发送请求
	var xhr = new XMLHttpRequest();
	var url="";              //地址，注意不要跨域
	xhr.open("post", url);
	xhr.setRequestHeader("content-type", "application/json");
	xhr.onreadystatechange = function() {
		if(xhr.readyState == 4) {
			var str=xhr.responseText;
			console.log(str);
			var obj=JSON.parse(str);
			if(typeof(fn)=="function"){
				fn(obj);
			}
		}
	}
	data=JSON.stringify(data);
	xhr.send(data);
}
//轮巡var Timer=setInterval(function(){ var xhr = new XMLHttpRequest(); var url=""; xhr.open("GET", url); xhr.setRequestHeader("content-type", "application/json"); xhr.onreadystatechange = function() {  if(xhr.readyState == 4) {  } }},2000);              // 200秒内持续
document.addEventListener(‘click‘,function(evt){
	if(!evt.target.matches(".yes")){
		return;
	}
	var data={                                         //发送的数据
		environ:document.getElementById("environ").checked,
		keystone:document.getElementById("keystone").checked,
		glance:document.getElementById("glance").checked,
	}
	postInstall(data,function(resdata){
		if(resdata.status=="OK"){
			alert("发送成功")；
		}
	});
});