為什么resizeImg函數不起作用？

<script>
                        img = document.getElementById("Arnold");
                        function enlargeImg() {
                            img.style.transform = "scale(1.5)";
                            img.style.transition = "transform 0.25s ease";
                        }
                        function resetImg() {
                            img.style.transform = "scale(1)";
                            img.style.transition = "transform 0.25s ease";
                        }           
                    </script>

放大功能運行良好，但重置功能卻不行，我不知道為什么。謝謝你