The scrollbar of <pre> will disappear during the animating? any ideas to solve this?

It looks during the animating of the pre tag, the scrollbar of pre wil开发者_运维问答l disappear, but appears later when animation is over. how can i make it appear in whole animation?

<script type="text/javascript">
$(document).ready(function(){   
        $('pre').hover(
                function(){
                    if($(this).width()==520){
                        $(this).animate({width:'800'},400);
                        $(this).css({border:'2px solid #2B99E6'});
                    }
                },
                function(){
                    if($(this).width()==800){
                        $(this).animate({width:'520'},400);
                        $(this).css({border:'2px solid #555555'});
                    }
                }
        );      
});
</script>

<style type="text/css">
pre {
    background: url("images/source.jpg") no-repeat scroll 0 0 #333333;
    border: 2px solid #555555;
    color: green;
    font-family: arial;
    margin: 0;
    overflow: scroll;
    padding: 30px 0 20px;
    position: relative;
    width: 520px;
    display: block;
}
</style>

<pre>
test it: www.gbin1.com
</pre>

change your css properties to

pre {
  overflow:scroll !important;
}

as done in this example http://jsfiddle.net/vTBV4/

however, the !important flag may not work in all browsers :( but as far as i know, this is the only way to ensure that the scroll is visible, as jquery animate implicitly sets the inline style overflow: hidden on the element to be animated.

Another option might be to create and animate a parent container instead of the <pre>.