效果：
HTML部分：
<html> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <style type = "text/css"> @import"mystyle.css" </style> <script src="index.js" type="text/javascript"></script> </head> <body> <div class= "test-css"> <form id = "form1" action="" method="post" class="STYLE-NAME" onsubmit = "return test()"> <h1>留言板实例 <span>填写下面的信息(*为必填).</span> </h1> <label> <!-- <span id = "bt">*</span> --> <span class = "c">ID :</span> <input id="name" type="text" name="name" placeholder="填写你的ID" /> </label> <label> <!-- <span id = "bt">*</span> --> <span class = "c">Email :</span> <input id="email" type="email" name="email" placeholder="请输入有效的Email地址" /> </label> <label> <span>留言 :</span> <textarea id="message" name="message" placeholder="请输入留言内容"></textarea> </label> <label> <span>注册信息 :</span><select name="selection"> <option value="Job Inquiry">已注册用户</option> <option value="General Question">游客</option> </select> </label> <label> <span> </span> <input type="button" class="button" value="确定" οnclick= test() /> </label> </form> </div> </body> </html> JS部分： function test(){ e = email.value; // i = name.value; i = document.getElementById("name"); if (i == ""){ alert("ID不能为空！") } if (e == ""){ alert("邮箱不能为空！"); return false; } var reg = /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/; ok = reg.test(e); if (!ok){ alert("邮箱格式不正确！"); return false; } } CSS部分： .test-css { margin-left:auto; margin-right:auto; max-width: 500px; background: #F8F8F8; padding: 30px 30px 20px 30px; font: 12px Arial, Helvetica, sans-serif; color: #666; border-radius: 5px; -webkit-border-radius: 5px; -moz-border-radius: 5px; } .test-css h1{ font: 24px "Trebuchet MS", Arial, Helvetica, sans-serif; padding: 20px 0px 20px 40px; display: block; margin: -30px -30px 10px -30px; color: #FFF; background: #9DC45F; text-shadow: 1px 1px 1px #949494; border-radius: 5px 5px 0px 0px; -webkit-border-radius: 5px 5px 0px 0px; -moz-border-radius: 5px 5px 0px 0px; border-bottom:1px solid #89AF4C; } .test-css h1>span { display: block; font-size: 11px; color: #FFF; } .test-css label { display: block; margin: 0px 0px 5px; } .test-css label>span { float: left; margin-top: 10px; color: #5E5E5E; } .c::before{ content : "*"; color : red; } .test-css input[type="text"], .test-css input[type="email"], .test-css textarea, .stest-css select { color: #555; height: 30px; line-height:15px; width: 100%; padding: 0px 0px 0px 10px; margin-top: 2px; border: 1px solid #E5E5E5; background: #FBFBFB; outline: 0; -webkit-box-shadow: inset 1px 1px 2px rgba(238, 238, 238, 0.2); box-shadow: inset 1px 1px 2px rgba(238, 238, 238, 0.2); font: normal 14px/14px Arial, Helvetica, sans-serif; } .test-css textarea{ height:100px; padding-top: 10px; } .test-css select { background: no-repeat right, -moz-linear-gradient(top, #FBFBFB 0%, #E9E9E9 100%); background: no-repeat right, -webkit-gradient(linear, left top, left bottom, color-stop(0%,#FBFBFB), color-stop(100%,#E9E9E9)); appearance:none; -webkit-appearance:none; -moz-appearance: none; text-indent: 0.01px; text-overflow: ''; width:100%; height:30px; } .test-css.button { background-color: #9DC45F; border-radius: 5px; -webkit-border-radius: 5px; -moz-border-border-radius: 5px; border: none; padding: 10px 25px 10px 25px; color: #FFF; text-shadow: 1px 1px 1px #949494; } .smart-green .button:hover { background-color:#80A24A; }