Javascript：跳转到指定页面

 <div>
     <input type="text" id="jumpPage"/>
     <input type="button" value="GO" onclick="Jump();" />
     Total Pages:<input type="text" id="totalPages" value="{{ pages }}" />
 </div>
 <script>
     function Jump() {
         var val = document.getElementById('jumpPage').value.trim()
         var totalPages = document.getElementById('totalPages').value.trim()
         if(isNaN(val) || Number(val)<1 || Number(val)>Number(totalPages)|| !(Number(val) %1 === 0)){
             alert("Please input a right page number")
             document.getElementById('jumpPage').value = null
             return false
         }else{
             location.href = "/index/"+val
         }
     }
 </script>