checkbox Multi-checkbox Linked implementation code

<script type="text/javascript">
function CheckboxGroup(){
var arrelement = ;
var i=0;
while(i<){
var forgroupattrib = arrelement[i].getAttribute('forcheckboxgroup');
if(forgroupattrib != null && forgroupattrib != ''){
arrelement[i].setAttribute('groupmember',_getGroupMember(arrelement[i]));
if(arrelement[i].() == 'input' && arrelement[i].type == 'checkbox'){
arrelement[i].onclick=function(){
//----------------------Checked All------------------
var groupmember = ('groupmember');
var i = 0;
while(i<){
groupmember[i].checked = ;
i++;
}
//---------------------------------------------------
}
}
_setState(arrelement[i]);
}
i++;
}
}

function _getGroupMember(o){
var groupname = ('forcheckboxgroup');
var items = new Array;
var inputs = ('input');
var i=0;
while(i<){
if(inputs[i].type == 'checkbox'){
var groupattrib = inputs[i].getAttribute('group');
if(groupattrib == groupname){
items[] = inputs[i];
var master = inputs[i].getAttribute('groupmaster');
if (master == null) {
master = new Array;
master[0] = ;
inputs[i].setAttribute('groupmaster', master);
}
else{
master[] = ;
}
inputs[i].onpropertychange = function(){
if ( == 'checked') {
var arro = ('groupmaster');
var i = 0;
while (i < ) {
_setState((arro[i]));
i++;
}
}
}
}
}
i++;
}
return items;
}

function _setState(o){
var master = o;
if(master!=null){
var chkselall = true;
var chknosel = true;
var groupmember = ('groupmember');
var i = 0;
while(i<){
if(chkselall)chkselall = groupmember[i].checked;
if(chknosel)chknosel = !groupmember[i].checked;
i++;
}
if(() == 'input'&&=='checkbox'){
if (chkselall) {
= false;
= true;
}
if (chknosel) {
= false;
= false;
}
if(!chkselall&&!chknosel) = true;
}
else{
= chknosel;
}
}
}

('onload',CheckboxGroup);
</script>