请问如何停止ajax当前的请求呀

function connectSuccess(){
        ++i;
         alert("ss1111111111111111111:"+i);
    }
    function ajaxReady(){
        var state=ajax.readyState;   
        switch(state){
            case 4:
               connectSuccess();
            break;
        }
    }
    function sendReq(){
          ajax.open("GET","[url=http://localhost:8080/appmanageWeb/application/video/]http://localhost:8080/appmanageWeb/application/video/[/url]韩国劲爆歌舞.MP4",false);
         ajax.send(false);
         ajax.abort();
     }
     sendReq();
请问为什么我这样写 还是能够执行请求呢