JavaScript-WeChat public number, the front desk to the background to initiate an AJAX request, the background can not get sent over the value is what??

Ecshop Backstage:
Public number Front Desk:

try{    function getData(method,path,searchStr,dataType,fn){      var xhr=new XMLHttpRequest();      method=method.toUpperCase();          xhr.open(method.toLowerCase(),(method==='POST') ? path : path+'?'+searchStr,true);          if (method==='POST'){            xhr.setRequestHeader('content-type','application/x-www-form-urlencoded');          }          xhr.send((method==='POST') ? searchStr : null);          xhr.onreadystatechange=function(){            if (this.readyState===4 && this.status===200){              var data=this.responseText;                           alert('fanyingshuju: '+data);            }          }    }    getData('GET','goods.php','act=price&id=' + goodsId + '&attr=' + attr + '&number=' + qty, changePriceResponse);      }catch(err){    alert('error: '+err);  }  

Background:

 die('发起的请求： '.$_REQUEST['act']);

This place is always getting no value, what the hell is going on??

Reply content:

Ecshop Backstage:
Public number Front Desk:

try{    function getData(method,path,searchStr,dataType,fn){      var xhr=new XMLHttpRequest();      method=method.toUpperCase();          xhr.open(method.toLowerCase(),(method==='POST') ? path : path+'?'+searchStr,true);          if (method==='POST'){            xhr.setRequestHeader('content-type','application/x-www-form-urlencoded');          }          xhr.send((method==='POST') ? searchStr : null);          xhr.onreadystatechange=function(){            if (this.readyState===4 && this.status===200){              var data=this.responseText;                           alert('fanyingshuju: '+data);            }          }    }    getData('GET','goods.php','act=price&id=' + goodsId + '&attr=' + attr + '&number=' + qty, changePriceResponse);      }catch(err){    alert('error: '+err);  }  

Background:

 die('发起的请求： '.$_REQUEST['act']);

This place is always getting no value, what the hell is going on??

Consider whether the cross-domain is

