var promise = new Promise((resolve, reject){
function captcha_validate(){
let request = new XMLHttpRequest();
let url = "/authentication/check_captcha";
let elem = document.getElementsByName('captcha')[0]
request.open('POST', url);
request.send(elem.value);
request.onreadystatechange = function(){
if ((request.readyState == 4) && (request.status == 200)){
let status = JSON.parse(request.responseText)['status'];
if (status == true){
set_highlight(elem);
reject(false);
}
else{
drop_highlight(elem);
resolve(true);
}
}
}
}
captcha_validate();
})
promise.then(y=>{console.log(y)}).catch(error=>{console.log(error)})