glitch in formData when posting

[am05mhz]

when posting something:

marmottajax({
    url: "post.php",
    method: "post",
    parameters: {
        image: 8,
        by: "click"
    }
}).success(function(result) {
    // result
}).error(function(message) {
    // message
});

the data that actually posted has an extra empty variable like:

?&image=8&by=click

which when received on the server side as {'?': '', image: 8, by: 'click'}