Copy this code and paste it in your HTML
<input type="radio" name="group" value="option1" id="option1"/><label for="option1">option 1
</label><br /> <input type="radio" name="group" value="option2" id="option2"/><label for="option2">option 2
</label><br /> <input type="radio" name="group" value="option3" id="option3"/><label for="option3">option 3
</label><br /> <input type="radio" name="group" value="option4" id="option4"/><label for="option4">option 4
</label><br />