Как сделать пустой участок в matplotlib?

В кодах HTML:

<form action="POST" onsubmit="ajax_submit();return false;">
    <b>First Name:</b> <input type="text" name="firstname" id="firstname">
    <br>
    <b>Last Name:</b> <input type="text" name="lastname" id="lastname">
    <br>
    <input type="submit" name="send" onclick="ajax_submit();">
</form>

В Js-кодах:

function ajax_submit()
{
    $.ajax({
        url: "submit.php",
        type: "POST",
        data: {
            firstname: $("#firstname").val(),
            lastname: $("#lastname").val()
        },
        dataType: "JSON",
        success: function (jsonStr) {
            // another codes when result is success
        }
    });
}