<form action="#" method="post" id="regFrom">
 <fieldset>
 <legend>个人基本信息</legend>
 <div>
 <label for="username">名称：</label>
 <input id="username" type="text" />
 </div>
 <div>
 <label for="pass">密码：</label>
 <input id="pass" type="passward" />
 </div>
 <div>
 <label for="msg">详细信息：</label>
 <textarea id="msg" ></textarea>
 </div>
 </fieldset>
 </form>

.focus{
 border: 1px solid #f00;
 background: #fcc;
 }

$(function(){
 $(':input').focus(function(){
 $(this).addClass('focus');
 }).blur(function(){
 $(this).removeClass('focus');
 });
 });

<form action="#" method="POST" id="regFrom">
 <div class="msg">
 <div class="msg_caption">
 <span class="bigger">放大</span>
 <span class="small">缩小</span>
 </div>
 <div>
 <textarea id="comment" rows="8" cols="20">
  多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，多行文本框，
 </textarea>
 </div>
 </div>
 </form>

$(function(){
 var $comment = $('#comment');
 $('.bigger').click(function(){
 if($comment.height() < 500){
 $comment.height( $comment.height() + 50 );
 }
 });
 $('.small').click(function(){
 if($comment.height() > 50){
 $comment.height( $comment.height() - 50 ); 
 }
 });
 });

$(function(){
 var $comment = $('#comment');
 $('.bigger').click(function(){
 if(!$comment.is(':animated')){
 $comment.animate({scrollTop : '-=50'},400);
 }
 });
 $('.small').click(function(){
 if(!$comment.is(':animated')){
 $comment.animate({scrollTop : '+=50'},400);
 }
 });
 });

<form action="#" method="POST" id="regFrom">
 <p>你爱好的运动</p>
 <input type="checkbox" name="items" value="足球" />足球
 <input type="checkbox" name="items" value="篮球" />篮球
 <input type="checkbox" name="items" value="羽毛球" />羽毛球
 <input type="checkbox" name="items" value="乒乓球" />乒乓球
 <br />
 <input type="button" id="CheckedAll" value="全 选" />
 <input type="button" id="CheckedNo" value="全不选" />
 <input type="button" id="CheckedRev" value="反 选" />
 <input type="button" id="send" value="提 交" />
 </form>

$('#CheckedAll').click(function(){
 $('[name=items]:checkbox').attr('checked',true);
 });
 $('#CheckedNo').click(function(){
 $('[name=items]:checkbox').attr('checked',false);
 });

 $('#CheckedRev').click(function(){
 $('[name=items]:checkbox').each(function(){
 this.checked = !this.checked;
 });
 });

var str = "你选中的是：\r\n";
 $('#send').click(function(){
 
 $('[name=items]:checkbox:checked').each(function(){
 str += $(this).val() + "\r\n";
 });
 alert(str);
 });

<div class="centent">
 <select multiple id="select1" style="width:100px;height:160px;">
 <option value="1" >选项1</option>
 <option value="2" >选项2</option>
 <option value="3" >选项3</option>
 <option value="4" >选项4</option>
 <option value="5" >选项5</option>
 <option value="6" >选项6</option>
 <option value="7" >选项7</option>
 <option value="8" >选项8</option>
 </select>
 <div>
 <span id="add">选中添加到右边>></span><br />
 <span id="add_all">全部添加到右边>></span>
 </div>
 </div>
 <div class="centent">
 <select multiple id="select2" style="width:100px;height:160px;"></select>
 <div>
 <span id="remove"><<选中删除到左边</span><br />
 <span id="remove_all"><<全部删除到左边</span>
 </div>
 </div>

 $('#add').click(function(){
 var $options = $('#select1 option:selected');
 $options.appendTo($('#select2'));
 });

 $('#add_all').click(function(){
 var $options = $('#select1 option');
 $options.appendTo($('#select2'));
 });

$('#select1').dblclick(function() {
 var $options = $('option:selected');
 $options.appendTo($('#select2'));
 });

<form methos="post" action="">
 <div class="int">
 <label for="username">用户名</label>
 <input type="text" id="username" class="required" />
 </div>
 <div class="int">
 <label for="email">邮箱</label>
 <input type="text" id="email" class="required" />
 </div>
 <div class="int">
 <label for="personinfo">个人资料</label>
 <input type="text" id="personinfo" />
 </div>
 <div class="sub">
 <input type="submit" value="提交" id="send" />
 <input type="reset" id="red" />
 </div>
 </form>

$('form :input').blur(function(){
 var $parent = $(this).parent();
 // 删除以前的提示元素
 $parent.find(".formtips").remove();
 // 验证用户名
 if($(this).is('#username')){
 if(this.value == '' || this.value.length < 6){
  var errorMsg = '请输入至少6位的用户名';
  $parent.append('<span class="formtips onError">'+errorMsg+' </span>');
 }else{
  var okMsg = '输入正确';
  $parent.append('<span class="formtips onSuccess">'+okMsg+'</span>');
 }
 }
 // 验证邮箱
 if($(this).is('#email')){
 if(this.value == '' || (this.value != "" && !/.+@.+\.[a-zA-Z] {2,4}$/.test(this.value))){
  var errorMsg = '请输入正确的E-Mail地址';
  $parent.append('<span class="formtips onError">'+errorMsg+' </span>');
 }else{
  var okMsg = '输入正确';
  $parent.append('<span class="formtips onSuccess">'+okMsg+'</span>');
 }
 }
 });

// 提交按钮
 $('#send').click(function(){
 $('form .required:input').trigger('blur');
 var numError = $('form .onError').length;
 if(numError){
  return false;
 }
 alert("注册成功");
 });