Ajax synchronous and asynchronous transmission sample code_javascript skills

//Synchronous transmission mode

function RequestByGet(nProducttemp ,nCountrytemp)
{
var xmlhttp

if (window.XMLHttpRequest)
{ //isIE = false;
xmlhttp = new XMLHttpRequest();
} 
else if (window.ActiveXObject) 
 {                                                                     }

/ /Web page location.
var URL="http://www.jb51.net/;
xmlhttp.open("GET",URL, false);
//xmlhttp.SetRequestHeader("Content -Type","text/html; charset=Shift_JIS")
xmlhttp.send(null);
var result = xmlhttp.status;

//OK
if(result= =200)
{
document.getElementById("div_RightBarBody").innerHTML=xmlhttp.responseText;
} 🎜>/ /Asynchronous transfer mode
var xmlhttp

function RequestByGet(nProducttemp,nCountrytemp)
{
if (window.XMLHttpRequest)
{
//isIE = false;     
xmlhttp = new XMLHttpRequest();
} else if (window.ActiveXObject)
{ //isIE = true;
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}

//Web page location.
var URL="http://www.jb51.net/";
xmlhttp.open("GET",URL, true) ;
xmlhttp.onreadystatechange = handleResponse;
//xmlhttp.SetRequestHeader("Content-Type","text/html; charset=UTF-8")
xmlhttp.send(null);
}

function handleResponse()
{
if(xmlhttp.readyState == 4 && xmlhttp.status==200)
{
document.getElementById("div_RightBarBody"). innerHTML=xmlhttp.responseText;
xmlhttp = null;
}
}