最近用到js筛选一个url的域名部分（草创）

var TLD = ['com','net','org','gov','edu','mil','biz','name','info','mobi','cn','hk'];

		var host = '';

		function start(){

		 	var regx = /(\w+\.){1,}\w+/;

		 	var inpt = document.getElementById('inpt');

		 	var txt = inpt.value.toLowerCase();

		 	var findTLD = function(arr){

		 		for(var j = 0;j<arr.length;j++){

		 			if(TLD.indexOf(arr[j])!=-1){

		 				return arr[j];

		 			}

		 		}

		 	};

		 	if(regx.test(inpt.value)){

		 		var matches = regx.exec(inpt.value)[0];

		 		var txtArr = matches.split('.');

		 		host = txtArr[txtArr.indexOf(findTLD(txtArr))-1];

		 		if(host){

		 			inpt.value = matches.slice(matches.indexOf(host));

		 		}else {

		 			alert('请输入正确的的URL');

		 		}

		 	}else{

		 		alert('请输入正确的的URL');

		 	}

		}