var btn = document.getElementById("a4");
???var usne = document.getElementById("username");
???var psw = document.getElementById("password");
???var usneTips1 = document.getElementById("username-tips1");
???var usneTips2 = document.getElementById("username-tips2");
???var pswTips = document.getElementById("password-tips");
???var secTips = document.getElementById("success-tips");
???btn.onclick ?= function () {
???????var usneValue = usne.value;
???????var pasValue = psw.value;
???????if(usneValue == ""&& pasValue==""){
???????????noneAll();
???????????pswTips.style.display="inline";
???????????usneTips2.style.display="inline";
???????}else if(usneValue != ""&& pasValue==""){
???????????noneAll();
???????????pswTips.style.display="inline";
?????????
???????}else if(usneValue == ""&& pasValue!=""){
???????????noneAll();
???????????usneTips2.style.display="inline";
?????????
???????}else if(usneValue != ""&& pasValue!=""){
???????????noneAll();
???????????if(usneValue.length==11||checkEmil(usneValue)==true){
???????????????noneAll();
???????????????secTips.style.display="block";
????????????window.setTimeout("https://www.yuque.com/dashboard",2000);
????????????
???????????}else{
???????????????usneTips1.style.display="inline";
???????????????usneTips1.style.color="red";
????????????
???????????}
???????}
???};
??
???function noneAll() {
???????pswTips.style.display="none";
???????usneTips2.style.display="none";
???????usneTips1.style.display="none";
???}
???function checkEmil(emil) {
???????var reg = new RegExp("^[a-z0-9]+([._\\-]*[a-z0-9])*@([a-z0-9]+[-a-z0-9]*[a-z0-9]+.){1,63}[a-z0-9]+$"); //正则表达式
???????var obj = emil;
?????if(!reg.test(obj)){ //正则验证不通过，格式不对
???????????console.log("fff");
???????????return false;
???????}else{
???????????console.log("ttt");
???????????return true;
???????}
???}
js登录界面代码自用
原文地址：https://www.cnblogs.com/160809113-yzl/p/10149465.html