jQuery – Object position on mousemove. Failed to set up easing.

Question

An object's position is updated relatively to mouseposition on mousemove (opposite direction). Works perfectly well, but I failed to set up the code with smooth easing as result. The code works in Actionscript (of course in proper syntax) but it doesn't work in jQuery syntax and code-elements. I use "css()" to position the object, "animate() with easing" produces a messy animation.

Any idea how I could implement an easing to this animation?

$().mousemove(function(e){

    $(".object").each(function(){

        var position = $(this).offset();
        var position_x = position.left;
        position_x = 0;

        var windowwidth = ($(window).width()/2);
        var endX = (windowwidth)-(e.pageX);

        var speed = 5;
        position_x += (endX-position_x)/speed;

        $(this).css({'left':position_x});

}); });