JSFiddle - React, Tailwind, and code Playground
by holden321
HTML
<body>
<form>
<p><strong>СТРАНИЦА</strong>
</p>
<input type='radio' name='page' value='1' id='page1' />
<label for='page1'>СТРАНИЦА1</label>
<br />
<input type='radio' name='page' value='2' id='page2' />
<label for='page2'>СТРАНИЦА2</label>
<br />
<input type='radio' name='page' value='3' id='page3' checked />
<label for='page3'>СТРАНИЦА3</label>
<br />
<p>
<label for='pagename'>Имя страницы<span class='alert'>*</span>
</label>
<br />
<input name='pagename' type='text' id='pagename' size='100' value='VALUE1' />
</p>
</form>
</body>
JavaScript
$(':radio[name=page]').change(function () {
$("#pagename").val($("label[for="+this.id+"]").text());
});