html頁面實現回車跳轉下一文本框

window.onload = function () {
    //阻止按回車按鈕后提交表單的問題
    document.getElementsByTagName("form")[0].onkeydown = function () {
        if (event.keyCode == 13) { return false; }
    };
    var inputs = document.getElementsByTagName("input");
    var index = 1;
    for (var i = 0; i < inputs.length; i++) {
        if (inputs[i].type == "text" && inputs[i].style.display != "none" && inputs[i].getAttribute("disabled") != "disabled") {
            //給頁面上的沒有隱藏的文本框設置tabindex順序值，下文按tabindex順序跳轉
            inputs[i].setAttribute("tabindex", index);
            //監聽onkeydown事件,輸入回車時實現跳至下一文本框
            inputs[i].onkeydown = goNextInput;
            index++;
        }
    }
};

function goNextInput() {
    if (window.event.keyCode == 13) { //錄入回車時才往下一錄入框跳
        //下一個錄入框的tabindex值
        var nextIndex = parseInt(window.event.srcElement.getAttribute("tabindex")) + 1;
        var inputs = document.getElementsByTagName("input");
        for (var i = 0; i < inputs.length; i++) {
            if (inputs[i].type == "text" && inputs[i].style.display != "none") {
                var tabIndex = inputs[i].getAttribute("tabindex");
                if (tabIndex != null) {
                    var index = parseInt(tabIndex);
                    if (typeof index == "number" && !isNaN(index) && index == nextIndex) {
                        inputs[i].focus();
                    }
                }
            }
        }
    }
}