尝试这样的事情：

<div id="LoadingImage" style="display: none">
  <img src="" />
</div>

<script>
  function ajaxCall(){
    $("#LoadingImage").show();
      $.ajax({ 
        type: "GET", 
        url: surl, 
        dataType: "jsonp", 
        cache : false, 
        jsonp : "onJSONPLoad", 
        jsonpCallback: "newarticlescallback", 
        crossDomain: "true", 
        success: function(response) { 
          $("#LoadingImage").hide();
          alert("Success"); 
        }, 
        error: function (xhr, status) {  
          $("#LoadingImage").hide();
          alert('Unknown error ' + status); 
        }    
      });  
    }
</script>