How to separately validate each simple HTML radio form, created through a PHP loop, using Javascript and Jquery

I made a number of html forms containing only radio buttons and a submit button. However, I cannot get them to validate properly--independently of each other. Here is my code:

PHP/HTML code for the form:

<table>
<?php
for($i=0; $i<count($array1); $i++)
{
  $number = $i + 1;
  echo "<TR><TD>;
  echo "<form name='move' action='listChange_controller.php' method='POST'>Title:<br/>
        <input type='radio' name='change".$number."' value = 'val1' />Thing1
        <input type='radio' name='change".$number."' value = 'val2'/>Thing2
        <input type='radio' name='change".$number."' value = 'val3'/>Thing3
        <input type='button' name='submit' value='submit' onClick='validate(".$number.");'/>";
  echo "</form>";
  echo "</TD></TR>";
开发者_C百科}
?>
</table>

Here is the javascript/jquery I have been trying, but has not worked:

function validate(number)
{
    var name_var = 'change'+number;
    if($('input:radio[name=name_var]:checked').length > 0)
    {
        $.post('file.php',{ name_var:$('input:radio[name=name_var]:checked').val()});
    }
    else
    {
       alert('You must choose');
       return false; 
    }
}

When I do this, it always thinks I have not chosen a radio button before pressing submit; it always carries out the 'else' part of my javascript function.

Please let me know why it is not working, and what would work. Any help and suggestions appreciated.

---

This line...

if($('input:radio[name=name_var]:checked').length > 0)

should read

if($('input:radio[name=' + name_var + ']:checked').length > 0)

---

Change...

if($('input:radio[name=name_var]:checked').length > 0)

to...

if ($('input[name=' + name_var + ']').is(':checked'))