Javascript上传脚本不起作用

Question

我正在使用此HTML表单上传图片：

     <form id="uploader_frm" method="post" 
           action="http://www.example.com/Admin/saveContentinplace.php?action=uploadPhoto" 
           onsubmit="return AIM.submit(this, {'onStart' : startCallback, 'onComplete' : completeCallback})" 
           enctype="multipart/form-data">
        <div align="right">
            <label>Pic</label>
            <input type="file" class="ENTextbox" name="photo" id="photo" style="width:295px;">
        </div>
        <br><br>
        <div align="center">
           <input type="submit" value="Upload" class="button">&nbsp;
           <input type="button" onclick="AddNewPic();document.location.reload();" value="Finish" class="button">
        </div>
        <input type="hidden" value="" name="itemID" id="itemID">
     </form>

这是处理上传的javascript函数：

    AIM = {
    frame : function(c) {

    var n = 'f' + Math.floor(Math.random() * 99999);
    var d = document.createElement('DIV');
    d.innerHTML = '<iframe style="display:none" src="about:blank" id="'+n+'" name="'+n+'" onload="AIM.loaded(\''+n+'\')"></iframe>';
    document.body.appendChild(d);

    var i = document.getElementById(n);
    if (c && typeof(c.onComplete) == 'function') {
        i.onComplete = c.onComplete;
    }

    return n;
    },

    form : function(f, name) {
    f.setAttribute('target', name);
    },

    submit : function(f, c) {
    AIM.form(f, AIM.frame(c));
    if (c && typeof(c.onStart) == 'function') {
        return c.onStart();
    } else {
        return true;
    }
    },

    loaded : function(id) {
    var i = document.getElementById(id);
    if (i.contentDocument) {
        var d = i.contentDocument;
    } else if (i.contentWindow) {
        var d = i.contentWindow.document;
    } else {
        var d = window.frames[id].document;
    }
    if (d.location.href == "about:blank") {
        return;
    }

    if (typeof(i.onComplete) == 'function') {
        i.onComplete(d.body.innerHTML);
    }
    }

    }

问题在于，当我提交表单时，我收到“未选择文件”且图片未上传。

服务器：运行apache 2.4.9和php 5.4.30

的Cenos 6.5