得到“;未捕获的异常:内存不足”;在firebug中执行ajax调用

我一直在尝试使用chrome和firefox调试ajax调用。我在这两方面都是新手。当使用chrome进行debbuging时，我得到了一个ajax响应，最后两个参数(jqXHR, textStatus, errorThrown)为空，第一个是xhr状态0。我有时会说，因为我有时会得到xhr状态200，而参数textStatus, errorThrown正在打印解析错误和意外字符"<"。我一直在查看我的php代码现在是因为我一直在做一个测试：对每个php代码进行注释，并返回php从ajax调用中获得的相同$_POST['json']，我得到了相同的错误。我一直在看我的json，它的格式很好。我被所有这些错误和我不太理解的令人困惑的调试工具弄糊涂了，我转到了firefox和firebug，在那里我得到了另一个不同的消息："未捕获的异常：内存不足"我一直在阅读其他一些开发人员提出的相同问题，并尝试了公认的答案，但我仍然找不到问题所在，这就是为什么我在这里发布我的代码，希望有人能提供帮助。非常感谢！

html代码：

                   <input type="submit" data-effect="mfp-zoom-out" value='Submit' onClick="setTypeAdvanced()" style= "
    position: relative;
    top: -152px;
    left: 129px;
" />

index.js:中的jscript代码

function setTypeAdvanced(){
    var advancedFormVars = {};
    /**SHOW*/
    if(document.getElementById('OfferID').checked == true){
        advancedFormVars['checkbox1'] = document.getElementById('OfferID').value;
    }
    if(document.getElementById('offerName').checked == true){
        advancedFormVars['checkbox2'] =document.getElementById('offerName').value;
    }
    if(document.getElementById('campaignID').checked == true){
        advancedFormVars['checkbox3'] = document.getElementById('campaignID').value;
    }
    if(document.getElementById('campaignName').checked == true){
        advancedFormVars['checkbox4'] = document.getElementById('campaignName').value;
    }
    if(document.getElementById('installs').checked == true){
        advancedFormVars['checkbox5'] = document.getElementById('installs').value;
    }
    if(document.getElementById('revenue').checked == true){
        advancedFormVars['checkbox6'] = document.getElementById('revenue').value;
    }

    /** FILTERS */
    if(document.getElementById('offerIDFilt').checked == true){
        advancedFormVars['checkbox7'] =  document.getElementById('offerIDFilt').value;
    }
    if(document.getElementById('publisherIDFilt').checked == true){
        advancedFormVars['checkbox8'] = document.getElementById('publisherIDFilt').value;
    }
    if(document.getElementById('publisherIDTextVal').value.length >'0'){
        advancedFormVars['checkbox9'] =  document.getElementById('publisherIDTextVal').value;
        publisherIDTextVal  =  document.getElementById('publisherIDTextVal').value;
    }
    if(document.getElementById('offIDTextVal').value.length > '0'){
        advancedFormVars['checkbox10'] =  document.getElementById('offIDTextVal').value;
    }
        /**GROUP BY*/
    if(document.getElementById('dates').checked == true){
        advancedFormVars['checkbox11'] = document.getElementById('dates').value;
    }
    if(document.getElementById('geos').checked == true){
        advancedFormVars['checkbox12'] = document.getElementById('geos').value;
    }
    if(document.getElementById('browsers').checked == true){//arreglar no coge checked, coge objeto html
        advancedFormVars['checkbox13']= document.getElementById('browsers').value;
    }
    if(document.getElementById('oS').checked == true){//arreglar coge undefined
        advancedFormVars['checkbox14'] = document.getElementById('oS').value;
    }


    /**ORDER BY*/
    if(document.getElementById('installsGroupBy').checked == true){
        advancedFormVars['checkbox15']= document.getElementById('installsGroupBy').value;
    }
    if(document.getElementById('revenueGroupBy').checked == true){
        advancedFormVars['checkbox16']= document.getElementById('revenueGroupBy').value;
    }
    advancedFormVars['none']= (typeof none=== 'undefined') ? 'default' : none;
    advancedFormVars['ASC']= (typeof ASC === 'undefined') ? 'default' : ASC;
    advancedFormVars['DESC']= (typeof DESC === 'undefined') ? 'default' : DESC;


    loadFormAdvanced(advancedFormVars);

}
function loadFormAdvanced(advancedFormVars){
    var json = JSON.stringify(advancedFormVars);
    $.ajax({
        url : 'AL_loadForm.php',
        type : 'POST',
        data : {
            json:json
        },
        dataType:'json',
        success : function(data) {
            alert(data);
        },
        error: function(jqXHR, textStatus, errorThrown) {
              alert('error '+errorThrown);
              alert('status '+textStatus);
              alert('xhr status '+jqXHR.status);
            }
    });
}

编辑以添加我的php代码：

<?php 
    if($_POST){ 
         if($_POST['json']){
              echo json_encode($_POST['json']); //also tryed echo($_POST['json']);
              } 
         }
?>

这是我的json:

{"checkbox1":"OfferID","checkbox2":"Offer Name","checkbox3":"CampaignID","checkbox4":"CampaignName","checkbox5":"Installs","checkbox6":"Revenue","checkbox7":"OfferID","checkbox8":"PublisherID","checkbox9":"some publisher","checkbox10":"some offer","checkbox12":"Geos","checkbox15":"Installs","none":"default","ASC":"default","DESC":"default"}

在ajax调用中发送之前，它已经从控制台日志中复制/粘贴：

var json = JSON.stringify(advancedFormVars);
console.log(json);
$.ajax({
    url : 'AL_loadForm.php',
    type : 'POST',
    data : {
        json:json
    },
    dataType:'json',
    success : function(data) {
        alert(data);