Validating radio[] array problem

[bhakti_thakkar]

hi all,
i have radio buttons for every group on my PHP page which populate dynamically from the DB:

Yes<INPUT TYPE="radio" NAME="rollback_<?=$arr['Audit_ID']?>" id="RollBackRadio[]" value="1"><br>
No<INPUT TYPE="radio" NAME="rollback_<?=$arr['Audit_ID']?>" id="RollBackRadio[]" value="0">

<script language="javascript">
function checkRadio(){
var radios = document.mainform.elements["RollBackRadio[]"];
var radflag=false;
for (var i=0; i<radios.length; i++){
if (radios[i].checked){
radflag=true;
} else {
radflag=false;
}
}
return radflag;
}

</script>
for eg ... if there are three audits on the page then there would be three sets of radio buttons. how do i validate that atleast one radio is checked for every Audit
Note : i cannot change the name of the radio button. probably would have to play with IDs. i tried giving id to the radio but the script is getting length as 6 [for the above case where audits are 3] instead of 3 ..
how can i do it??
Thanks in advance.

[shyam]

if u can't change the name then change the id

Yes<INPUT TYPE="radio" NAME="rollback_1" id="RollBackRadio0_1" value="1"><br>
No<INPUT TYPE="radio" NAME="rollback_1" id="RollBackRadio0_0" value="0">

and check if anything is selected by using the group number of the radio in this case 0

function checkRadio(group){
	var cnt = 0;
	var el = document.getElementById('RollBackRadio' + group + '_' + cnt);
	var flag = false;
	while ( !!el && !flag ) {
		flag = el.checked;
		cnt++;
		el = document.getElementById('RollBackRadio' + group + '_' + cnt);
	} // endwhile
	alert( (flag ? 'something' : 'nothing') + ' is selected');
	return flag;
}

[bhakti_thakkar]

Hi Shyam,

Thanks for the helpful reply

Originally Posted by shyam

if u can't change the name then change the id

Yes<INPUT TYPE="radio" NAME="rollback_1" id="RollBackRadio0_1" value="1"><br>
No<INPUT TYPE="radio" NAME="rollback_1" id="RollBackRadio0_0" value="0">

and check if anything is selected by using the group number of the radio in this case 0

function checkRadio(group){
	var cnt = 0;
	var el = document.getElementById('RollBackRadio' + group + '_' + cnt);
	var flag = false;
	while ( !!el && !flag ) {
		flag = el.checked;
		cnt++;
		el = document.getElementById('RollBackRadio' + group + '_' + cnt);
	} // endwhile
	alert( (flag ? 'something' : 'nothing') + ' is selected');
	return flag;
}

[BarrMan]

Originally Posted by shyam

if u can't change the name then change the id

Yes<INPUT TYPE="radio" NAME="rollback_1" id="RollBackRadio0_1" value="1"><br>
No<INPUT TYPE="radio" NAME="rollback_1" id="RollBackRadio0_0" value="0">

and check if anything is selected by using the group number of the radio in this case 0

function checkRadio(group){
	var cnt = 0;
	var el = document.getElementById('RollBackRadio' + group + '_' + cnt);
	var flag = false;
	while ( !!el && !flag ) {
		flag = el.checked;
		cnt++;
		el = document.getElementById('RollBackRadio' + group + '_' + cnt);
	} // endwhile
	alert( (flag ? 'something' : 'nothing') + ' is selected');
	return flag;
}

Hey, Shyam. What does the !!el mean?

[shyam]

well its just a fancy way of checking if a particular object/property is present...the idea is that a double negative cancel each other out so the output is always a boolean !!'', !!null, !!undefined and !!0 all return false...pretty much everything else returns true

[BarrMan]

I see. That's a nice trick.

Thanks