谷歌浏览器弹框报错：Error:status code is 0

谷歌浏览器报错：Error:status code is 0<div class="from">                     <input id="ss_text" name="suggest" type="text" value="搜索小组、帖子、课程..." onkeydown="search_sub(this,event)" />                        <img id="ss_img" onclick="search_sub(this,event)" style="cursor:pointer" src="http://s3.jsyxw.cn/res/sq/images/search/sousuo.jpg" alt="搜索" />                        <form id="ss_form" action="" method="post"></form>                    </div>                    <script type="text/javascript">                       function search_sub(ele,event){                                    var ss_text = document.getElementById('ss_text').value;                                    if(ss_text == '搜索小组、帖子、课程...')return;                                    if(ss_text){                                        var e = event || window.event;                                        if(ele.tagName == 'IMG' || e.keyCode == 13){                                            var ss_form = document.getElementById('ss_form');                                            ss_form.action = 'http://sq.yanxiu.com/search/search.at?appName=all&suggest='+ss_text;                                            ss_form.submit();                                            }                                            }                                            }                    </script>
就是上面这段代码，键盘事件，当按下回车键的时候就提交表单页面跳转，但是在谷歌浏览器会弹出一个警告框Error:status code is 0，是为什么？别的ie,ff都好使~·不解。