The value property represents the VALUE attribute of the HTML tag used to create the radio button.
<html>
<head>
<title> Example of the radio value property</title>
</head>
<body>
<form name="form1">
<input type="radio" name=button1 value=1>Box 1
<br><br>
<input type="button" value="Get Button Value"
onClick='alert("The button value is: " + document.form1.button1.value)'>
</form>
</body>
</html>