我有两个下拉框,"combo1"和"combo2",
如果我在combo1中选择任何值,我需要在JavaScript中将相同的值作为"selected"选中combo2。应该添加什么JavaScript代码到下面的HTML中使其起作用?
<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>