window.onload = function () {

            // 點按鈕1將按鈕2與3停用
            document.getElementById("button1").onclick = function () {
                document.getElementById("button2").setAttribute("disabled", "disabled");
                document.getElementById("button3").setAttribute("disabled", "disabled");
            };

            // 點按鈕2將按鈕1與3停用
            document.getElementById("button2").onclick = function () {
                document.getElementById("button1").setAttribute("disabled", "disabled");
                document.getElementById("button3").setAttribute("disabled", "disabled");
            };

            // 點按鈕3將按鈕1與2停用
            document.getElementById("button3").onclick = function () {
                document.getElementById("button1").setAttribute("disabled", "disabled");
                document.getElementById("button2").setAttribute("disabled", "disabled");
            };

            // 同場加映：3 秒後恢復原狀
            document.getElementById("button1").addEventListener("click", function () {
                setTimeout(
                    "document.getElementById('button2').removeAttribute('disabled');document.getElementById('button3').removeAttribute('disabled');",
                    3000)
            });

            document.getElementById("button2").addEventListener("click", function () {
                setTimeout(
                    "document.getElementById('button1').removeAttribute('disabled');document.getElementById('button3').removeAttribute('disabled');",
                    3000)
            });

            document.getElementById("button3").addEventListener("click", function () {
                setTimeout(
                    "document.getElementById('button1').removeAttribute('disabled');document.getElementById('button2').removeAttribute('disabled');",
                    3000)
            });

        }