onClick: how to get the value of radio button??

[MohsinAli]

I have three radio buttons in my form.

How can I get the value of selected radio button.

[ScallioXTX]

<input type="radio" id="myRadio1" value="1" name="some_name" />
<input type="radio" id="myRadio2" value="2" name="some_name" />
<input type="radio" id="myRadio3" value="3" name="some_name" />

var value = false;
if (document.getElementById('myRadio1').checked) {
   value = document.getElementById('myRadio1').value;
} else if (document.getElementById('myRadio2').checked) {
   value = document.getElementById('myRadio2').value;
} else if (document.getElementById('myRadio3').checked) {
   value = document.getElementById('myRadio3').value;
}
 
if (value !== false) {
   alert('Value of selected radio is ' + value);
} else {
   alert('Please select an option');
}

Please be careful to use !== and not !=
!== says that the value should not have the same value as false, and that it should be of the same type (boolean).
if you use != and one of the values is -1, the script goes wrong.