html-radio

inf: http://www.w3schools.com/html/html_forms.asp

Radio Buttons

<input type="radio"> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of choices:

<form>
<input type="radio" name="sex" value="male">Male<br>
<input type="radio" name="sex" value="female">Female
</form>

How the HTML code above looks in a browser:

Male
Female