stupid-lookat.js

var normalizedMousePos = {x: 0, y: 0};

function animHandler(props) {
    props.lookAroundAlpha = {x: normalizedMousePos.x, y: -normalizedMousePos.y, z: 0};
    return props;
}

Controller.mouseMoveEvent.connect(function (e) {
    normalizedMousePos.x = ((2 * e.x) / Window.innerWidth) - 1;
    normalizedMousePos.y = ((2 * e.y) / Window.innerHeight) - 1;
});

animHandlerId = MyAvatar.addAnimationStateHandler(animHandler, ["lookAroundAlpha"]);

Script.scriptEnding.connect(function () {
    MyAvatar.removeAnimationStateHandler(animHandlerId);
});