var fileInput = document.querySelector('input[type=file]');



fileInput.addEventListener('change', function(e){
    /* (1) On rédige la requête */
    var request = {
        path: 'upload/call_log',
        file: fileInput.files[0]
    };

    /* (2) On effectue l'upload (import) */
    api.send(request, function(response){
        console.log( response );
    });

}, false);