Getting the value of selected radio buttons

[phantomlimb]

Hi,

I have a bit of a tricky question here, i have several radio button groups in my form. They share the same name 'ptag' as i am storing them in a PHP variable eg.

<input type="radio" name="ptag[group1]" value="g1a" />
<input type="radio" name="ptag[group1]" value="g1b" />
<input type="radio" name="ptag[group2]" value="g2a" />
<input type="radio" name="ptag[group2]" value="g2b" />
<input type="radio" name="ptag[group3]" value="g3a" />
<input type="radio" name="ptag[group3]" value="g3b" />

The user can select one option from each of the three groups, so i want to show what the user has selected in a div tag without refreshing the page.

I have attempted some code below, and while i don't get any JS errors, i'm also getting no value passed, i suspect i am not retrieving the value correctly, any ideas on how i could rework the code below to get the values of selected radio buttons.

<script type="text/javascript">
function get_radio_value()
{
for (var i=0; i < document.filterform.ptag.length; i++)
   {
   if (document.filterform.ptag[i].checked)
      {
      var rad_val = document.filterform.ptag[i].value;
	  var somediv = document.getElementById('someid');
          somediv.innerHTML = document.filterform.ptag[i].value;
      }
   }
}
</script>

[Kor]

In javascript the value of an attribute is a string, thus "ptag[group1]" does not substitute an array so that the special characters "[]" have no special meaning. It's just a simple string, same as "foo", "fee0011" or "blah[_98i[[".

That means you have 3 independent radio groups and there is no "natural" way to refer them as a "global" group. To do that, you should work a little bit on the code, using a RegExp match and an array to capture the values. Could be something like this:

function get_radio_value(){
var rads=document.getElementsByTagName('input'), i=0, val=[], r;
	while(r=rads[i++]){
		if(r.type=='radio'&&r.name.match(/ptag/g)&&r.checked){
		val[val.length]=r.value;
		}
	}
//now the values of the checked radios are "captured" into the array called val
document.getElementById('someid').innerHTML=val.join(',');
}