[Ajax] ajax script

var req = null;

function callAjax(url) {
   
    var reqValue = "";

    if(url == "a_next.jsp") {
        
        reqValue = loginParamValue();
       // reqValue = url + "?" + encodeURIComponent(loginParamValue());  //한글 처리
    }else {
       
        reqValue = transParamValue();
    }
   
    req = getXMLHTTPRequest();

    req.open("POST", url, true);
    //req.open("GET", url, true); // true : 비동기 방식(응답이 올때까지 기다리지 않는다.), false : 동기 방식(응답이 올때까지 아무것도 못하고 기다린다.)
   
    req.setRequestHeader('Content-Type','application/x-www-form-urlencoded;charset=UTF-8');
    req.setRequestHeader("Cache-Control","no-cache, must-revalidate");
    req.setRequestHeader("Pragma","no-cache");

    req.onreadystatechange = callback;
    req.send(reqValue); //request
    //req.send(null);
}

function callback() {
   
    if (req.readyState == 4) {   //완료
        if (req.status == 200) { //오류없이ok

            var str = req.responseText;  //서버에서 보낸 내용 받기
            document.getElementById("message").innerHTML = str;
        }else {
            alert("Fail : " + req.status);
        }
    }
}
 
function getXMLHTTPRequest() {
   
    var req = false;
  
    try {

        req = new XMLHttpRequest(); //firefox, mozilla...
    }catch(err1) {

        try {

            req = new ActiveXObject("Microsoft.XMLHTTP"); //IE 6.0 ~
        }catch(err2) {

            try {
              
                req = new ActiveXObject("Msxml2.XMLHTTP"); // ~ IE 5.0
            }catch(err3) {
      
                req = false;
            }
        }

    }
   
 return req;
}//xmlHttpRequest return
 
function loginParamValue() {
   
    var param = "";
   
    //login
    var id = document.getElementById("id");
    var pub = document.getElementById("pub");
    var pri = document.getElementById("pri");
   
    //login
    param = "id=" + id.value;                             
    param += "&" + "pub=" + pub.value;  
    param += "&" + "pri=" + pri.value; 
   
    return param;   
}//loginParamValue return

function transParamValue() {
   
    var param = "";
   
    //trans information
    var id = document.getElementById("id");
    var cd = document.getElementById("cd");
    var spversion = document.getElementById("spversion");

    param = "id=" + id.value;
    param += "&" + "cd=" + cd.value;
    param += "&" + "spversion=" + spversion.value;  
    
    return param;   
}//transParamValue return