Issues with javascript validation of radio buttons on php form - php

Question

This is the code for the php file containing the form with radio buttons:
<?php
while($r7 = mysql_fetch_array($rt3)){
$name=$r7["name"];
$s=$r7["question"];
echo "
<div>$s</div>
<form name='Tester' method='post' onSubmit='return RegValidate(this);' action='quest.php' >
<input type='radio' name='w1' value='1'>1<br>
<input type='radio' name='w1' value='2'>2<br>
<input type='radio' name='w1' value='3'>3<br>
";
}
echo" <input name='Submit' value='Tester' type='submit' />
</form>";
?>
The $name and $q are derived from the database using a mysql query. This works fine.
I have used the following javascript code so far:
function RegValidate(Tester)
{
if($('#w1').not(':checked'))
{
alert('Radio not checked');
return false;
}
}
But with this code, I continue to get the error message, and I am not able to move on even though I have selected a radio button.
The while loop produces several sets of radio buttons, as $q, gets the question from the database and posts it on the page along with 3 radio buttons. Each question $q, has the 3 radio buttons in the above, hence the reason for the $name.
How do I validate this form with javascript. NB. The form will only contain radio buttons.

Answer 1

function RegValidate(Tester) {
if ($(":radio[name=w1]:checked").toArray().length == 0) {
alert('nothing selected');
return false;
}
}​
FIDDLE

Answer 2

you have an error, your input doesn't have ID or CLASS, so add to all of the input radio class='w1' and try the next code:
if ($(".w1 option:selected").length<1)
alert ('nothing selected');
also take a look to this post: Check if option is selected with jQuery, if not select a default

Answer 3

do these things:
<input type='radio' class='w1' name='w1' value='1'>1<br>
<input type='radio' class='w1' name='w1' value='2'>2<br>
<input type='radio' class='w1' name='w1' value='3'>3<br>
And in js:
Latest edit:
if ( $(':radio[class=w1]').attr('checked') != 'checked' ) {
alert('Radio not checked');
}