comet4j js中写法

<script type="text/javascript" src="${ctxStatic}/common/js/comet4j.js"></script>
<%--<script type="text/javascript">
   var projectPath = "<%= request.getContextPath()%>";
       function cometdCallback(text){
           var kbDom = document.getElementById('num1');
           kbDom.innerHTML = text;
       }
       function init() {
           JS.Engine.on({
               number : cometdCallback
           });
           JS.Engine.start("<%= request.getContextPath()%>/conn");
       }
   window.onload = init;
</script>--%>