Ajax Upload

const formData = new FormData();

formData.append("username", "Groucho");
formData.append("accountnum", 123456);

const fileInputElement = document.getElementById( 'myFile' );
formData.append( fileInputElement.name, fileInputElement.files[0], fileInputElement.files[0].name );
formData.append("userfile", fileInputElement.files[0]);
formData.append("webmasterfile", new Blob(['<a><b>hey!</b></a>'], { type: "text/xml"}), "data.xml");

const xhr = new XMLHttpRequest();
xhr.open("POST", "http://foo.com/submitform.php");
xhr.onload = function(){
    if ( xhr.status >= 200 && xhr.status < 400 )
        console.log( "Response: " + xhr.responseText );
};
xhr.onerror = function(){
    console.log( "Failed" );
};
xhr.send(formData);