Solved.
Remember to put <!-- --> around script code!
Ex
<script type="text/javascript">
<!--
$(document).ready(function() {
$(".accordion h3:first").addClass("active");
$(".accordion p:not(:first)").hide();
$(".accordion h3").click(function() {
$(this).next("p").slideToggle("fast")
.siblings("p:visible").slideUp("fast");
$(this).toggleClass("active");
$(this).siblings("h3").removeClass("active");
});
});
-->
</script>