function ajaxGetRequest(path, callback){
let request = new XMLHttpRequest();
request.onreadystatechange = function(){
if (this.readyState === 4 && this.status === 200){
callback(this.response);
}
};
request.open("GET", path);
request.send();
}
function ajaxPostRequest(path, data, callback){
let request = new XMLHttpRequest();
request.onreadystatechange = function(){
if (this.readyState === 4 && this.status === 200){
callback(this.response);
}
};
request.open("POST", path);
request.send(data);
}
var xhr = new XMLHTTPRequest();