JSFiddle - React, Tailwind, and code Playground

HTML

<table><tr><td><b>Gender*:</b></td>
<td><input id="Male" name="Gender" type="radio" >Male<br/>
    <input id="Female" name="Gender" type="radio">Female</td></tr></table>
    <a href="#" onclick="checkGender()">Go</a>

JavaScript

function checkGender(){
    var Gender = document.getElementsByName('Gender');
    genderSelected = false;
    for(var i=0; i < Gender.length; i++)
        if(Gender[i].checked)
            genderSelected = true;
    if(!genderSelected) { alert('Please select your gender.'); return false; }
}