etTimeout来实现setInterval

etTimeout来实现setInterval

 <script type="text/javascript">
 function interval(func, w, t){
     var interv = function(){
         if(typeof t === "undefined" || t-- > 0){
             setTimeout(interv, w);
             try{
                 func.call(null);
             }
             catch(e){
                 t = 0;
                 throw e.toString();
             }
         }
     };
 
     setTimeout(interv, w);
 };
 
 </script>