placeholder 不支持IE修复

<script type="text/javascript">
var JPlaceHolder = {
//检测
_check : function(){
return 'placeholder' in document.createElement('input');
},
//初始化
init : function(){
if(!this._check()){
this.fix();
}
},
//修复
fix : function(){
jQuery(':input[placeholder]').each(function(index, element) {
var self = $(this), txt = self.attr('placeholder');
self.wrap($('<div></div>').css({position:'relative', zoom:'1', border:'none', background:'none', padding:'none', margin:'none'}));
var pos = self.position(), h = self.outerHeight(true), paddingleft = self.css('padding-left');
var holder = $('<span></span>').text(txt).css({position:'absolute', left:20, top:pos.top, height:h, lienHeight:h, paddingLeft:paddingleft, color:'#aaa'}).appendTo(self.parent());
self.focusin(function(e) {
holder.hide();
}).focusout(function(e) {
if(!self.val()){
holder.show();
}
});
holder.click(function(e) {
holder.hide();
self.focus();
});
});
}
};
$(function(){

JPlaceHolder.init();
})
</script>