File Upload in Ajax

$("form#data").submit(function(){

    var formData = new FormData($(this)[0]);

    $.ajax({
        url: window.location.pathname,
        type: 'POST',
        data: formData,
        async: false,
        success: function (data) {
            alert(data)
        },
        cache: false,
        contentType: false,
        processData: false
    });

    return false;
});

Short Version

$("form#data").submit(function() {
    var formData = new FormData($(this)[0]);
    $.post($(this).attr("action"), formData, function(data) {
        alert(data);
    });
    return false;
});

$.ajax({
    url: 'php/upload.php',
    data: $('#file').attr('files'),
    cache: false,
    contentType: 'multipart/form-data',
    processData: false,
    type: 'POST',
    success: function(data){
        alert(data);
    }
});