How to get the value of radio button.!!!

Dr-Wordpress : through Php How to get the value of radio button...!!!

<form name="my form" method="POST" action="validate.php"> 
<label >
  <input type="radio" id="id_radio1" name="name_radio" value="1"/>Dr-wordpress 1</label>
<label>
    <input type="radio" id="id_radio2" name="name_radio" value="2"/>Dr-wordpress 2</label>
<label>
     <input type="radio" id="id_radio3" name="name_radio" value="3"/>Dr-wordpress 3</label>

<input type="submit">
</form>

NOTE : Must gave the value in input tag other wise just ON/OFF will display 

<?php

if(isset($_POST['submit']))
{
    echo $radio_value1 = $_POST["name_radio"];
}
?>

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