<style>
    html, body {
        margin: 0;
        padding: 0;
    }
    rect {
        fill: none;
        stroke-width: 6;
        stroke-linejoin: round;
        stroke: green;
        width: 100px;
        height: 100px;
    }
</style>
<body>
    <svg>
        <rect x="10" y="10"/>
    </svg>
    <script>
        function moveRect(rect) {
            var x = parseFloat(rect.getAttribute("x"));
            var y = parseFloat(rect.getAttribute("y"));
            rect.setAttribute('x', x + 10);
            rect.setAttribute('y', y + 10);
        }

        (function() {
            var element = document.elementFromPoint(10, 10);
            if (element instanceof SVGRectElement)
                moveRect(element);

            element = document.elementFromPoint(20, 20);
            if (element instanceof SVGRectElement)
                moveRect(element);
        })();
    </script>
</body>