如何使用JavaScript更改组合框中的"选定"值?

Ale*_*lex 4 javascript combobox

我有2个组合框,"combo1"和"combo2",

如果我在combo1中选择任何值,我需要在combo2中使用与JavaScript"选中"相同的值.应该在下面的HTML中添加哪些JavaScript代码才能使其正常工作?

<html>
    <head>
        <title>combo</title>
    </head>

    <body>
        <form name="testForm" action="" method="post">
            <select name="combo1">
                <option value="1">option 1</option>
                <option value="2">option 2</option>
                <option value="3">option 3</option>
            </select><br /><br />
            <select name="combo2">
                <option value="1">option 1</option>
                <option value="2">option 2</option>
                <option value="3">option 3</option>
            </select>
        </form>
    </body>
</html>
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rah*_*hul 12

<script type='text/javascript'>
    window.onload = function() { BindEvent(); }

    function BindEvent()
    {
        var elemToBind = document.getElementById ( "cmb1" );
        elemToBind.onchange = function () { SetSel ( this ); }
    }
    function SetSel(elem)
    {
        var secondCombo = document.getElementById ( "cmb2" );
        secondCombo.value = elem.value;   
    }
</script>
<body>
    <select id="cmb1">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
    </select>
    <select id="cmb2">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
    </select>
</body>
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  • @Alex:整个句子中的spk. (3认同)