checked radio button html code example
Example 1: html radio button checked
<input type="radio" id="huey" name="drone" value="huey"
checked>
<!-- https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/radio-->
Example 2: javascript radio button value if checked
//alert(document.querySelector('input[name = "comp"]:checked').value);
$test=document.querySelector('input[name = "comp"]:checked').value;
if($test="silver") {
amount=50;
}else if($test="gold") {
amount=90;
}else{
amount=30;
}