I want to animate the image which is clicked by the user to the top left 100x100 then I want it to return to its original position where the animation started but with this piece of code it keeps sliding by some pixels to the top and left. I couldn't figure out what causes this problem. How can I make it return to its original position?

```
var posLeft;
var posTop;

$(this).children("img").click(function() {

        goToTopLeft($(this));

        $.each($(this).parent().children("img"), function() {

            $(this).css("z-index","0");

        });

        goToFrontFromTopLeft($(this));

        $(this).css("z-index", "1");

    });

function goToTopLeft(img) {
        posLeft = img.position().left;
        posTop = img.position().top;
        img.animate({ top: '-=100', left: '-=100', height: 'toggle' }, 500);
    }

    function goToFrontFromTopLeft(img) {
        img.animate({ top: posTop, left: posLeft, height: 'toggle' }, 500);
    }

```