完成登录与注册页面的HTML+CSS+JS，其中的输入项检查包括：
用户名6-12位
首字母不能是数字
只能包含字母和数字
密码6-12位
注册页两次密码是否一致
html代码：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>欢迎你，请先登陆！</title> <script type="text/javascript" src="https://www.jb51.net/static/jsp/lx.js"></script> <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"> <link href="https://www.jb51.net/static/css/lx.css"> </head> <body> <div> <h2>登陆</h2> <div> <input type="text" placeholder="请输入用户名"> </div> <div> <input type="password" placeholder="请输入密码"> </div> <div><br></div> <div> <button type="button">登陆</button>     <a href="https://www.jb51.net/regist.html"><input type="button" value="注册"></a> </div> </div> </body> </html>
css代码：
*{ margin: 0; padding: 0; font-family: 微软雅黑; font-size: 12px; } .box{ width: 390px; height: 320px; border: solid 1px #ddd; background: #FFF; position: absolute; left: 50%; top:42%; margin-left: -195px; margin-top: -160px; text-align: center; } .box h2{ font-weight: normal; color:#666; font-size: 16px; line-height: 40px; overflow: hidden; text-align: center; border-bottom: solid 1px #ddd; background: #f7f7f7; } .input_box{ width:350px; padding-bottom: 15px; margin: 0 auto; overflow: hidden; }
javascript代码：
function fnLogin() { var oUname = document.getElementById("uname") var oUpass = document.getElementById("upass") var oError = document.getElementById("error_box") var isError = true; if (oUname.value.length > 20 || oUname.value.length < 6) { oError.innerHTML = "用户名请输入6-20位字符"; isError = false; return; }else if((oUname.value.charCodeAt(0)>=48) && (oUname.value.charCodeAt(0)<=57)){ oError.innerHTML = "首字符必须为字母"; return; }else for(var i=0;i<oUname.value.charCodeAt(i);i++){ if((oUname.value.charCodeAt(i)<48)||(oUname.value.charCodeAt(i)>57) && (oUname.value.charCodeAt(i)<97)||(oUname.value.charCodeAt(i)>122)){ oError.innerHTML = "必须为字母跟数字组成"; return; } } if (oUpass.value.length > 20 || oUpass.value.length < 6) { oError.innerHTML = "密码请输入6-20位字符" isError = false; return; } window.alert("登录成功") }
注册界面html代码：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>欢迎你，请先登陆！</title> <script type="text/javascript" src="https://www.jb51.net/static/jsp/lx.js"></script> <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"> </head> <body> <div> <div> <h2>注册</h2> </div> <div> <p>账号: <input type="text" placeholder="账号首字符为字母"> </p> <p>密码: <input type="password" placeholder="请输入密码"> </p> <div><br></div> <br> <button>注册</button> </div> <div> <i>版权信息@</i> </div> </div> </body> </html>
运行结果如下：
