function login ( ) {
    var username = document.getElementById ( "form-username" ).value;
    var password = document.getElementById ( "form-password" ).value;
    hashedpassword = SHA512 ( password );
    var xhr = new XMLHttpRequest ( );
    xhr.open ( "POST", 'login', true );
    xhr.onreadystatechange = function ( ) {
        if ( xhr.status == 200 ) {
            if ( xhr.readyState == XMLHttpRequest.DONE ) {
                var response = xhr.responseText;
                response = JSON.parse ( response );
                if ( response [ 'status' ] == 200 ) {
                    window.location.href = script_name;
                }
            }
        }
        else {
            document.getElementById ( 'login-response' ).innerHTML = JSON.parse ( xhr.responseText ) [ 'error_message' ];
            setTimeout( function( ) {
                document.getElementById ( 'login-response' ).innerHTML = ""
            }, 1500 );
        }
    }
    data = new FormData ( );
    data.append('username', username);
    data.append('password', password);
    data.append('hashedpassword', hashedpassword);
    xhr.send( data );
}

$(function ( ) {
    $( '.form-group input' ).keyup( function ( e ) {
        if ( e.keyCode == 13 ) {
            login();
        }
    });
});