下拉隐藏值

Drop Down hiding values

本文关键字：隐藏      更新时间：2023-09-26

我希望仅当用户选择月份而不是空白值时才显示 1 的日值，但它不起作用......我认为该功能是错误的。 我希望当天的 1 下拉列表仅在未选择月份时才显示 none。 请帮助我....

<html>
<head>
<script type="text/javascript">
function show(x) {
var mon = document.getElementById(x).innerHTML
if (mon == "") {
document.getElementById("one").style.display="none";
} else {
document.getElementById("one").style.display="";
}
}
</script>
</head>
<body>
Calendar<br>
<hr align="left" width="200px"/>

--Year ------ Month ----- Day<br>
<select name="year">
<option value="defaulty"></option>
<option value="2012">2012</option>
<option value="2013">2013</option>
<option value="2014">2014</option>
<option value="2015">2015</option>
</select>
<select name="month" onchange="show(this)">
<option id="defaultm"></option>
<option id="January">January</option>
<option id="February">February</option>
<option id="March">March</option>
<option id="April">April</option>
<option id="May">May</option>
<option id="June">June</option>
<option id="July">July</option>
<option id="August">August</option>
<option id="September">September</option>
<option id="October">October</option>
<option id="November">November</option>
<option id="December">December</option>
</select>
<select name="day">
<option id="defaultd" value="defaultd"></option>
<option id="one" value="one" style="display:none">1</option>
</select>
</body>
</html>

所以您希望日列仅在月份选择正确时才可用？如果我理解正确，这将解决问题。

<html>
<head>
    <script type="text/javascript">
        function show() {
            if (document.getElementById("month").selectedIndex != 0) {
                document.getElementById("day").disabled = false;
            }
            else {
                document.getElementById("day").disabled = true;
            }
        }
    </script>
</head>
<body>
    Calendar<br>
    <hr align="left" width="200px"/>
    <form actn="">
        --Year ------ Month ----- Day<br>
        <select name="year" id="year">
            <option value="defaulty"></option>
            <option value="2012">2012</option>
            <option value="2013">2013</option>
            <option value="2014">2014</option>
            <option value="2015">2015</option>
        </select>
        <select name="month" id="month" onchange="show()">
            <option value="defaultm"></option>
            <option value="January">January</option>
            <option value="February">February</option>
            <option value="March">March</option>
            <option value="April">April</option>
            <option value="May">May</option>
            <option value="June">June</option>
            <option value="July">July</option>
            <option value="August">August</option>
            <option value="September">September</option>
            <option value="October">October</option>
            <option value="November">November</option>
            <option value="December">December</option>
        </select>
        <select name="day" id="day" disabled="disabled">
            <option id="defaultd" value="defaultd"></option>
            <option id="one" value="one">1</option>
        </select>
    </form>
</body>

相关文章：