实用的placeholder插件，兼容IE下的placeholder，jquery插件

 1 /* 2 ?* jQuery placeholder, fix for IE6,7,8,9 3 ?* @website itmyhome.com 4 ?*/ 5 var JPlaceHolder = { 6 ????//检测 7 ????_check : function(){ 8 ????????return ‘placeholder‘ in document.createElement(‘input‘); 9 ????},10 ????//初始化11 ????init : function(){12 ????????if(!this._check()){13 ????????????this.fix();14 ????????}15 ????},16 ????//修复17 ????fix : function(){18 ????????jQuery(‘:input[placeholder]‘).each(function(index, element) {19 20 ????????????var self = $(this), txt = self.attr(‘placeholder‘);21 ????????????self.wrap($(‘<div></div>‘).css({position:‘relative‘, zoom:‘1‘, border:‘none‘, background:‘none‘, padding:‘none‘, margin:‘none‘}));22 ????????????var pos = self.position(), h = self.outerHeight(true), paddingleft = self.css(‘padding-left‘);23 24 ????????????var holder = $(‘<span></span>‘).text(txt).css({position:‘absolute‘, left:pos.left, top:pos.top, height:h, lienHeight:h, paddingLeft:paddingleft, color:‘#aaa‘}).appendTo(self.parent());25 ????????????self.focusin(function(e) {26 ????????????????holder.hide();27 ????????????}).focusout(function(e) {28 ????????????????if(!self.val()){29 ????????????????????holder.show();30 ????????????????}31 ????????????});32 ????????????holder.click(function(e) {33 ????????????????holder.hide();34 ????????????????self.focus();35 ????????????});36 ????????});37 ????}38 };39 40 //执行41 jQuery(function(){42 ????JPlaceHolder.init(); ???43 });