Possible Duplicate:
How do I access style properties of pseudo-elements with jQuery?
First,hover the block will rotation 40deg!!
How to change .block:hover from 40deg to 80deg when click button ??
CSS
<style type="text/css">
.block{
    -moz-transition:All 1s ease;
    -moz-transform: rotate(1deg);
    width:200px; height:100px;
background-color:#999;
}
.block:hover{
    -moz-transform: rotate(40deg);
}
</style>
HTML
<button id="change">» Run</button><br><br>
<div class="block">TEST</div>
JS
<script>
$("#change").click(function(){
//???
});
</script>
 
     
     
     
     
    