var httpRequest = null;

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

function sendRequest(urls, 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 = urls;
  
  if(httpMethod != 'GET' && httpMethod!=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);
}