jquery 支持ie6下position为fixed的方法

<!--[if lte IE 7]>

<script type="text/javascript">

(function($) {

$.fn.pozFixed = function(params) {

var defaults = {

top : 400,

left : '50%',

interval:100

};

defaults = $.extend(defaults,params);

return this.each(function(i,o) {

var $this = $(this);

this.fixPosition = function() {

var st = $().scrollTop();

$this.css({

top:st + defaults.top,

left:'50%'

});

};

$this.css({position:'absolute',top:defaults.top,left:"50%"});

setInterval(this.fixPosition,defaults.interval);

});

};

})(jQuery);

</script>

<![endif]-->
http://be-evil.org/post-116.html