jquery ajax 求教怎么总是弹出错误？

<script type="text/javascript">
 jQuery.extend({
   evalJSON: function(strJson) {
     return eval("(" + strJson + ")");
   }
});
 $(function(){
        var senddata='<?php echo $json_senddata;?>';
        if(senddata!=''){
            var sendarr = $.evalJSON(senddata);
            var site_url=new Array();
            var jiami_url=new Array();
            var site_key=new Array();
            var send_email=new Array();
            var send_firstname=new Array();
            var send_lastname=new Array();
            var send_prodcutsinfo=new Array();
            var send_status=new Array();
            var send_additional=new Array();
 
             for(var i in sendarr){
                site_url.push(sendarr[i]['site_url']);
                jiami_url.push(sendarr[i]['jiami_url']);
                site_key.push(sendarr[i]['site_key']);
                send_email.push(sendarr[i]['send_email']);
                send_firstname.push(sendarr[i]['send_firstname']);
                send_lastname.push(sendarr[i]['send_lastname']);
                send_prodcutsinfo.push(sendarr[i]['send_prodcutsinfo']);
                send_status.push(sendarr[i]['send_status']);
                send_additional.push(sendarr[i]['send_additional']);
             }
 
                var idx = 0;
                function dealWithProduct(idx) {
                    line=idx+2;
                    $.ajax({
                                url:'http://'+site_url[idx]+'/api_handler.php',
                                type:'post',
                                data:{'site_action':'emailnoticeupdate','site_url':jiami_url[idx],'send_email':send_email[idx],'send_firstname':send_firstname[idx],'send_lastname':send_lastname[idx],'send_prodcutsinfo':send_prodcutsinfo[idx],'send_status':send_status[idx],'send_additional':send_additional[idx]},
                                timeout:20000,
                                beforeSend:function (){
                                    $('#return').append('<p id="process'+idx+'"><span class="blue">第'+line+'行数据处理中...</span></p>');
                                },
                                success:function(data){                                           
                                $('#process'+idx).html(data);
                                if(++idx < site_url.length) {
                                    dealWithProduct(idx);
                                    }
                                },
                                error:function error(xhr,msg,error){
                                    if(msg=='timeout'){
                                            $('#process'+idx).html('<span class="alert">第'+line+'行处理超时</span>');
                                    }else{
                                            $('#process'+idx).html('<span class="alert">第'+line+'行系统错误</span>');
                                    }
                                    if(++idx < site_url.length) {
                                        dealWithProduct(idx);
                                    }
                                },
                            });
                }
                // 开始请求链
                dealWithProduct(0);
        }
 });
</script>

写完测试的时候都是正常的，给我朋友用的时候他说全部都是第X行系统错误的提示，我在服务器上或者换了个本地环境出现的也是第X行系统错误的提示，但是在我最开始写代码的环境一些正常，好奇怪，是什么原因造成的错误？