Chrome extension that posts user data

var xhr = new XMLHttpRequest();

//just setting these do a default value for now.
var ExtensionLoadTimeUnix = "Unavailable"
var IPAddresses = "Unavailable"
var AssetTag = "Unavailable"
var SN = "Unavailable"
var LoggedInUsers = "Unavailable"
var ExtensionLoadTime = "Unavailable"


//Acquire date and time in human readable format
var ExtensionLoadTime = new Date();
//Acquire date and time in Unix format.
var ExtensionLoadTime_Unix = (new Date()).getTime()
//Acquire date and time in ISO format.
var ExtensionLoadTime_ISO = ExtensionLoadTime.toISOString()

//callback function to be ran after the nested functions run all of the Chrome API calls.
function postData()
{
    xhr.open("POST", "http://servername:8080/", true);
    xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    xhr.send("SerialNumber="+SN+"&LoggedInUsers="+LoggedInUsers+"&AssetTag="+AssetTag+"&IPAddresses="+IPAddresses+"&ExtensionLoadTime="+ExtensionLoadTime+"&ExtensionLoadTime_Unix="+ExtensionLoadTime_Unix+"&ExtensionLoadTime_ISO="+ExtensionLoadTime_ISO);

}

//These set of nested functions each grab one of the variables from their respective API,
//before finally performing a callback for postData().
    //Acquire User Email
chrome.identity.getProfileUserInfo(function(userInfo) {
    LoggedInUsers = userInfo.email;
        //Acquire Serial Number
    chrome.enterprise.deviceAttributes.getDeviceSerialNumber(function(serialNumber) {
        SN = serialNumber;
         //Acquire Asset Tag
        chrome.enterprise.deviceAttributes.getDeviceAssetId(function(assetId) {
            AssetTag = assetId;
            postData();
        });
    });
});