/* new ajax object */
function createXmlHttpRequest() 
{
  var xmlRequest = false;
	
  if(window.XMLHttpRequest){
    xmlRequest = new XMLHttpRequest();
    
	if(xmlRequest.overrideMimeType){
	  xmlRequest.overrideMimeType('text/xml');    
	}
	
  }else if(window.ActiveXObject){
    try{
	  xmlRequest = new ActiveXObject("Msxml2.XMLHTTP");
	} catch(trymicrosoft){
	  try{
        xmlRequest = new ActiveXObject("Microsoft.XMLHTTP");
      }catch(failed){
        xmlRequest = false;
      }
	}
  }
  
  return xmlRequest;
}
/* send request require*/
function sendRequest(url,parameter,callback)
{
    xmlRequest = createXmlHttpRequest();

    if(xmlRequest)
    {
        xmlRequest.onreadystatechange = callback;
        xmlRequest.open("POST",url,true);
        xmlRequest.setRequestHeader("Content-type","application/x-www-form-urlencoded");
        xmlRequest.send(parameter);
        
    }else{
        alert("ajax error");
        return;
    }
}