Jquery 循环内间隔执行 异步执行

<script type="text/javascript">
var arr = new Array();
var arrk = 0;
jQuery(function() {
arr[0] = "aaa.keleyi.com";
arr[1] = "bbb.keleyi.com";
arr[2] = "ccc.keleyi.com";
mytime = setInterval(function(){showme()}, 2000);
function showme(){
alert(arr[arrk]);
arrk += 1;
if(arrk>2) clearInterval(mytime);
}
});
</script>