jQuery block moving

I wanna move a div blo开发者_开发知识库ck to the top, so I coded like this:

CSS part:

.movingPart{
margin-top:80px;
}

jQuery part:

$(document).ready(function() {

$('#btn').click(function() {


    $('.movingPart').animate({
        "margin-top":'0px'

    });


});

});

it works perfectly in chrome, but doesn't move a little in firefox, why???

thanks in advance

The jQuery docs indicate that you should use camelCase for properties when using animate.

Note that properties should be specified using camel case, e.g. "marginLeft" instead of "margin-left."