<!-- html代码 -->
    <!-- 背景云层 -->
    <div id="header">
      <div id="clouds">
          <div class="cloud-1" data-speed="35000"></div>
          <div class="cloud-2" data-speed="45000" data-delay="15000"></div>
          <div class="cloud-3" data-speed="40000"></div>
          <div class="cloud-4" data-speed="38000" data-delay="20000"></div>
      </div>
</div><!-- / #header -->

  <div id="content">
      <div class="container">            
          <!-- 登录模块 -->
          <form id="login" method="post" action="login.jsp" onsubmit="return checkForm(this);">
              <div id="login_header"><i class="icon-home"></i>智能小区服务管理系统</div>
              
              <div id="login_content">
                  <span>
                      <input class="tip" name="username" type="text" maxlength="18" onclick="onClick(this);" onblur="onBlur(this);">
                      <label for="username">用户名</label>
                      <i class="icon-user"></i>
                      <div class="tooltip" data-text="填写您的身份证号">填写您的身份证号</div>
                  </span>
                  <span>
                      <input class="tip" name="password" type="password" maxlength="16" onclick="onClick(this);" onblur="onBlur(this);">
                      <label for="password">密码</label>
                      <i class="icon-lock"></i>
                      <div class="tooltip" data-text="填写您的密码">填写您的密码</div>
                  </span>
                  <div class="option">
                      <div class="option_result">用户类型</div>
                      <div class="option_arrow"><b class="arrow"></b></div>
                      <ul class="option_list">
                          <li>住户</li>
                          <li>管理员</li>
                          <li>运营商</li>
                      </ul>
                      <div class="tooltip" data-text="选择您的用户类型">选择您的用户类型</div>
                  </div><!-- / .option -->
              </div><!-- / #login_content -->

              <div id="login_footer">
                  <div class="ing"></div>
                  <button id="login_btn" type="submit">登录</button>
              </div><!-- / #login_footer -->

              <div><a id="register_link" href="javascript:void(0);">新用户注册</a></div>
          </form><!-- / #login -->

          <!-- 注册模块 -->
          <form id="register" method="post" action="register.jsp" onsubmit="return checkForm(this);">
              <div id="register_header"><i class="icon-home"></i>新用户注册</div>
              
              <div id="register_content">
                  <span>
                      <input class="tip" name="realname" type="text" maxlength="4" onclick="onClick(this);" onblur="onBlur(this);">
                      <label for="realname">真实姓名</label>
                      <i class="icon-user"></i>
                      <div class="tooltip" data-text="填写您的真实中文姓名">填写您的真实中文姓名</div>
                  </span>
                  <span>
                      <input class="tip" name="ID" type="text" maxlength="18" onclick="onClick(this);" onblur="onBlur(this);">
                      <label for="ID">身份证号</label>
                      <i class="icon-lock"></i>
                      <div class="tooltip" data-text="填写您的真实身份证号码">填写您的真实身份证号码</div>
                  </span>
                  <span>
                      <input class="tip" name="password" maxlength="16" type="password" onclick="onClick(this);" onblur="onBlur(this);">
                      <label for="password">密码</label>
                      <i class="icon-lock"></i>
                      <div class="tooltip" data-text="填写6~16个字母或者数字">填写6~16位字母或者数字</div>
                  </span>
              </div><!-- / #register_content -->

              <div id="register_footer">
                  <div class="ing"></div>
                  <button id="register_btn" type="submit">注册</button>
              </div><!-- / #register_footer -->

              <div><a id="login_link" href="javascript:void(0);">返回登录</a></div>
          </form><!-- / #register -->

      </div><!-- / .container -->
  </div><!-- / #content-->

  <div id="footer">
      
      <div class="container">

      </div><!-- / .container -->

  </div><!-- / #footer -->
css代码
/* #Reset & Basics (Inspired by E. Meyers)
================================================== */
    html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
        margin: 0;
        padding: 0;
        border: 0;
        font-size: 100%;
        font: inherit;
        vertical-align: baseline; }
    article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section {
        display: block; }
    body {
        line-height: 1; }
    ol, ul {
        list-style: none; }
    blockquote, q {
        quotes: none; }
    blockquote:before, blockquote:after,
    q:before, q:after {
        content: '';
        content: none; }
    table {
        /*border-collapse: collapse;*/
        border-spacing: 0; }

/* #Basic Styles
================================================== */
    body {
        background:#87CEFA;
        overflow:hidden;
        font:normal 16px/1.5 Helvetica, "Microsoft Yahei", Arial, sans-serif;
        color:#444;
        -webkit-font-smoothing:antialiased; /* Fix for webkit rendering */
        -webkit-text-size-adjust:100%;
    }
    input {padding:10px 15px;outline:0;border:0;border-radius:3px;width:200px;}
    a, a:visited { color: #333; text-decoration: none; outline: 0; }
    a:hover, a:focus { color: #000;}

/*云层*/
    #clouds{position:absolute;top:0;right:0;bottom:0;left:0;}
    [class^="cloud-"]{position:absolute;right:120%;width:200px;height:60px;background:white;-webkit-border-radius:200px;-moz-border-radius:200px;border-radius:200px;}
    [class^="cloud-"]:before,[class^="cloud-"]:after{content:'';position:absolute;top:-15px;left:10px;width:100px;height:80px;background:#fff;-webkit-border-radius:100px;border-radius:100px;-webkit-transform:rotate(30deg);-moz-transform:rotate(30deg);transform:rotate(30deg);}
    [class^="cloud-"]:after {top: -55px;left: auto;right: 15px;width: 120px;height: 120px;}
    .cloud-1 {top: 50px;-webkit-animation: moveclouds 30s linear infinite;-moz-animation: moveclouds 30s linear infinite;-o-animation: moveclouds 30s linear infinite;animation: moveclouds 30s linear infinite;}
    .cloud-2 {top: 100px;opacity: 0.8;-webkit-transform: scale(0.8);-moz-transform: scale(0.8);transform: scale(0.8);-webkit-animation: moveclouds 45s linear infinite;-moz-animation: moveclouds 45s linear infinite;-o-animation: moveclouds 45s linear infinite;animation: moveclouds 45s linear infinite;-webkit-animation-delay: 5s;-moz-animation-delay: 5s;animation-delay: 5s;}
    .cloud-3 {top: 150px;opacity: 0.6;-webkit-transform: scale(0.6);-moz-transform: scale(0.6);transform: scale(0.6);-webkit-animation: moveclouds 40s linear infinite;-moz-animation: moveclouds 40s linear infinite;-o-animation: moveclouds 40s linear infinite;animation: moveclouds 40s linear infinite;}
    .cloud-4 {top: 200px;opacity: 0.75;-webkit-transform: scale(0.75);-moz-transform: scale(0.75);transform: scale(0.75);-webkit-animation: moveclouds 26s linear infinite;-moz-animation: moveclouds 26s linear infinite;-o-animation: moveclouds 26s linear infinite;animation: moveclouds 26s linear infinite;-webkit-animation-delay: 8s;-moz-animation-delay: 8s;animation-delay: 8s;}
    /*云层移动*/
    @-webkit-keyframes moveclouds {
        0%   { right: -20%; }
        100% { right: 120%; }
    }
    @-moz-keyframes moveclouds {
        0%   { right: -20%; }
        100% { right: 120%; }
    }
    @-o-keyframes moveclouds {
        0%   { right: -20%; }
        100% { right: 120%; }
    }


/* #Content Styles
================================================== */    
    /*内容*/
    #content{width:100%;}
    .container{width:960px;margin:0 auto;text-align:center;}
    /*登录/注册*/
    #login,#register{width:400px;height:380px;position:absolute;top:50%;left:50%;margin-top:-200px;margin-left:-200px;background:#F8F8F8;border-radius:10px;box-shadow:0 3px 6px rgba(0, 0, 0, 0.5);}
    #register{left:120%;}
    #login_header,#register_header{height:60px;line-height:60px;font-size:20px;font-weight:bold;color:#77CA60;background:#FFF;border-radius:10px 10px 0 0;-webkit-box-shadow:0 1px 3px rgba(0, 0, 0, .1);-moz-box-shadow:0 1px 3px rgba(0, 0, 0, .1);box-shadow:0 1px 3px rgba(0, 0, 0, .1);}
    .icon-home{font-size:30px;position:relative;top:3px;}

    #login_content,#register_content{height:200px;padding:30px 20px;}
    input{width:300px;padding:14px 15px;background:#F0F0F0;font:normal 16px/1.5 Helvetica,"Microsoft Yahei",Arial,sans-serif;color:#444;}
    span{position:relative;display:inline-block;height:50px;margin-bottom:30px;}
    .tip{text-indent:80px;-webkit-transition:all .3s ease-in-out;-moz-transition:all .3s ease-in-out;transition:all .3s ease-in-out;}
    .tip:focus,.tip:active{text-indent:0;}
    .tip + label{position:absolute;top:16px;left:15px;-webkit-transition:all .3s ease-in-out;-moz-transition:all .3s ease-in-out;transition:all .3s ease-in-out;}
    .tip:focus + label,.tip:active + label{-webkit-transform:translateY(-40px);-moz-transform:translateY(-40px);transform:translateY(-40px);}
    .icon-user,.icon-lock{position:absolute;top:16px;right:14px;color:#999;}
    .tooltip{width:200px;padding:14px;position:absolute;left:20%;top:0;right:0;color:#999;background:white;text-align:left;z-index:-1;box-shadow:0 1px 3px rgba(0, 0, 0, .1);}
    .tooltip:after{width:0;height:0;content:"";position:absolute;right:100%;top:18px;color:#87CEFA;border:8px solid;border-right-color:white;}

    #login_footer,#register{}
    #login_btn,#register_btn{width:100%;height:60px;line-height:60px;outline:0;border:none;color:white;font-weight:bold;font-size:20px;background:#77CA60;border-radius:0 0 10px 10px;cursor:pointer;text-shadow:1px 1px 1px rgba(0, 0, 0, 0.3);}
    .ing{width:100%;height:5px;position:absolute;bottom:60px;}

    #register_link,#login_link{width:80px;display:block;margin:20px auto;color:white;border-bottom:1px dashed;}

    /*下拉菜单*/
    .option{width:330px;position:absolute;margin:0 0 0 15px;text-align:left;background:#F0F0F0;cursor:pointer;border-radius:3px;}
    .option_result{display:inline-block;padding:11px 15px;}
    .option_arrow{padding:10px 19px;float:right;}
    .option_arrow .arrow{width:0;height:0;font-size:0;border:6px solid;border-color:#6F7880 #F0F0F0 #F0F0F0;}
    .option_list{background:#F3F3F3;display:none;}
    .option_list li{padding:10px 15px;float:none;}
    .option_list li:hover{background:#DFDFDF;}

    Javascript代码
    /**
	 * 输入框被点击
	 */
	function onClick(){

		//对函数的第一个参数进行判断
		if (arguments[0]) {
			var obj = arguments[0];
		}else{
			return false;
		}

		//获取.tooltip
		var tooltip = $(obj).siblings('.tooltip');
		//.tooltip如果存在，就滑出
		if (tooltip.length != 0) {
			//对函数第二个参数进行判断
			if (arguments[1]) {
				var text = arguments[1];
			}else{
				text = tooltip.data('text');
			}
			//设置提示框文字
			tooltip.text(text);
			//滑出提示框
			tooltip.animate({left:'120%'});
		};
	}
	
	/**
	 * 输入框失去焦点
	 */
	function onBlur(){
		//对函数的第一个参数进行判断
		if (arguments[0]) {
			var obj = arguments[0];
		}else{
			return false;
		}

		//获取.tooltip
		var tooltip = $(obj).siblings('.tooltip');
		//.tooltip如果存在，就滑入
		if (tooltip.length != 0) {
			tooltip.animate({left:'20%'});
		};
	}

	/**
	 * 表单验证
	 */
	function checkForm(){
		//对函数的第一个参数进行判断
		if (arguments[0]) {
			//获取当前表单
			var form = arguments[0];
		}else{
			return false;
		}

		//验证规则汇总
		var id = new RegExp(/[0-9]{18}/);//匹配数字18次，用于身份证号码匹配
		var password = new RegExp(/\w{6,16}/);//字母6到16次，用于密码匹配
		var chinese = new RegExp(/[^\u4e00-\u9fa5]|^$/);//匹配中文以外的字符，用于真实姓名验证
		var email = new RegExp(/\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/);//用于邮箱格式验证

		//用户名username验证(同样适用身份证验证)
		if (form.username != undefined && !id.test(form.username.value)) {
			//不符合匹配规则
			onClick($(form.username)[0],'身份证号码不规范，应为18位数字');
			//阻止页面跳转
			return false;
		};

		//密码password验证
		if (form.password != undefined && !password.test(form.password.value)) {
			//不符合匹配规则
			onClick($(form.password)[0],'密码不规范，应为6~16位字母和数字');
			//阻止页面跳转
			return false;
		};

		//用户类型type验证
		if ($(form).find('.option_result').text() == '用户类型') {
			//用户没有勾选
			onClick($('.option_result')[0],'请选择用户类型');
			//阻止页面跳转
			return false;
		};

		//真实姓名realname验证
		if (form.realname != undefined && chinese.test(form.realname.value)) {
			//有非中文字符
			onClick($(form.realname)[0],'姓名不规范');
			//阻止页面跳转
			return false;
		};

		//真实身份证号码id验证
		if (form.ID != undefined && !id.test(form.ID.value)) {
			//不符合匹配规则
			onClick($(form.ID)[0],'身份证号码不规范，应为18位数字');
			//阻止页面跳转
			return false;
		};

		//邮箱email验证
        if (form.email != undefined && !email.test(form.email.value)){
        	//不符合匹配规则
        	onClick($(form.email)[0],'不是有效地电子邮件地址');
        	//阻止页面跳转
        	return false;
        };
	}


	$(document).ready(function(){
		/**
		 * 展开/收起下拉列表
		 */
		$('.option').click(function(){
			$(this).children('.option_list').slideToggle(100);
			$(this).toggleClass('active');
		});

		/**
		 * 设置option的值
		 */
		$('.option_list li').click(function(){
			//获取选择的值
			var text = $(this).text();
			//设置option的值
			$(this).parent().siblings('.option_result').text(text);
			//如果存在就收起提示栏
			var tooltip = $(this).parent();//原生js的parentNode是属性而不是方法
			if (tooltip.length != 0) {
				onBlur(tooltip[0]);//需要传入原生js对象
			};
		});

		/**
		 * 切换到注册栏
		 */
		$('#register_link').click(function(){
			//滑出#login栏，滑入#register栏
			$('#login').animate({left:'-100%'},400,function(){
				$('#register').animate({left:'50%'});
			});
		});

		/**
		 * 切换到登陆栏
		 */
		$('#login_link').click(function(){
			//滑出#register栏，滑入#login栏
			$('#register').animate({left:'120%'},400,function(){
				$('#login').animate({left:'50%'});
			});
		});

		/**
		 * 登录
		 */
		$('#login_btn').click(function(){
			var $obj = $(this);
			$obj.text('登录中...');
			setTimeout(function(){
				$obj.text('登录');
			},5000);
		});

		/**
		 * 注册
		 */
		$('#register_btn').click(function(){
			var $obj = $(this);
			$obj.text('注册中...');
			setTimeout(function(){
				$obj.text('注册');
			},5000);
		});

		

	});