Three ways to get XMLHttpRequest object

//1
function getXMLHttpRequest() {
var xmlHttpReq;
try { // Firefox, Opera 8.0+, Safari
xmlHttpReq = new XMLHttpRequest();
} catch (e) {
try {// Internet Explorer
xmlHttpReq = new ActiveXObject("");
} catch (e) {
try {
xmlHttpReq = new ActiveXObject("");
} catch (e) {
}
}
}
return xmlHttpReq;
}

//2
function getXMLHttpRequest() {
var xmlHttpReq = null;
if () {// Internet Explorer
xmlHttpReq = new ActiveXObject(".3.0");
} else if () {
xmlHttpReq = new XMLHttpRequest();
}
return xmlHttpReq;
}

//3
function getXMLHttpRequest() {
var xmlHttpReq = null;
if () {// Mozilla Firefox, Opera 8.0+, Safari
xmlHttpReq = new XMLHttpRequest();
} else {
if () {// Internet Explorer
try {
xmlHttpReq = new ActiveXObject("");
} catch (e) {
try {// Internet Explorer
xmlHttpReq = new ActiveXObject("");
} catch (e) {
}
}
}
}
return xmlHttpReq;
}