请问C3100中例子Http server中POST方式如何取得返回值？

我在底层返回GET没问题，但返回POST是web页面显示无内容。
下位机代码
if(pal_Memcmp(ptr, CAN_POST_token, pal_Strlen(CAN_POST_token)) == 0)[
  processCANsend(ptr);
  ptr = pResponse->ResponseData.token_value.data;
  pResponse->ResponseData.token_value.len = 0;
 pal_Strcpy(ptr, "["id"=182,"data"="30 31 32 33 34 35 36 37"]");
pResponse->ResponseData.token_value.len += pal_Strlen(ptr);
]
上位机代码：
function SendPacket1()
[
var params = "__SL_P_UCA=";  //"__SL_P_UDW=";
params += document.getElementById("CAN_ID").value;
params += ",";
params += document.getElementById("CAN_Data").value;
params += ",";

HTTPrequest.open("POST","No_content", true);
HTTPrequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
HTTPrequest.setRequestHeader("Content-length", params.length);
HTTPrequest.setRequestHeader("Connection", "close");
HTTPrequest.onreadystatechange = function()
[
if (HTTPrequest.readyState==4 && HTTPrequest.status==200)
[
            text1 = HTTPrequest.responseText;
]
]
HTTPrequest.send(params);
]

监控所得，下位机确实运行代码了，但web返回状态为204