Calculate distance between center of two HTML objects

// get center position of an html element
function getPositionAtCenter(element) {
    var data = element.getBoundingClientRect();

    return {
        x: data.left + data.width / 2,
        y: data.top + data.height / 2
    };
}

// get distance between two elements
function getDistanceBetweenElements(a, b) {
    var aPosition = getPositionAtCenter(a);
    var bPosition = getPositionAtCenter(b);

    return Math.sqrt(Math.pow(aPosition.x - bPosition.x, 2) + Math.pow(aPosition.y - bPosition.y, 2));
}


function get_distance() {
    var distance = getDistanceBetweenElements(
        document.getElementById(object1), document.getElementById(object2)
    );

    return distance;
}