Ajax httpRequest.js

var SERVICE_URL = '상수 url';

function getXMLHttpRequest(){
 if(window.ActiveXObject){
  try{
   return new ActiveXObject("Msxml2.XMLHTTP");
  }catch(e){
   try{
    return new ActiveXObject("Microsoft.XMLHTTP");
   }catch(e1){
    return null;
   }
  }
 }else if(window.XMLHttpRequest){
  return new XMLHttpRequest();
 }else{
  return null;
 }
}
var httpRequest = null;

function sendRequest(url, params, callback, method){
 httpRequest = getXMLHttpRequest();
 var httpMethod = method ? method : 'GET';
 if(httpMethod != 'GET' && httpMethod != 'POST'){
  httpMethod = 'GET';
 }
 var httpParams = (params == null || params == '') ? null : params;
 var httpUrl = url;
 if(httpMethod == 'GET' && httpParams != null){  
  httpUrl = httpUrl + "?" + httpParams;
 }
 httpRequest.open(httpMethod, httpUrl, true);
 httpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 httpRequest.onreadystatechange = callback;
 httpRequest.send(httpMethod == 'POST' ? httpParams : null);
}