I have 2 comboboxes, "combo1" and "combo2",

If I select any value in combo1, I need that same value in combo2 as "selected" by JavaScript. What JavaScript code should be added to the HTML below to make it work?

```
<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>

```