check uncheck functionality in prototype.js in magento

Question

There is a label (class=lblnewsletter) and checkbox (id=is_subscribed).
When I click on label and if the checkbox is checked the alert will come 111 other wise it return 222.
I have wrote the following code but not working.
Please help.

$$('.lblnewsletter')[0].observe('click', function () {
 if($$('#is_subscribed').checked){
 alert(111);
 }else{
 alert(222);
 }
});

Answer 1

if you have id then used that

 $('is_subscribed').observe('click', function () {
 if($('is_subscribed').checked){
 alert(111);
 }else{
 alert(222);
 }
});

• AKSHAYA KUMAR Satapathy: As per requirement that solution is ok. But now I am implementing the function as below:
• AKSHAYA KUMAR Satapathy: $$('#is_subscribed')[0].observe('click', function () { if($$('#is_subscribed').checked){ $$('.lblnewsletter').addClassName('chked'); }else{ $$('.lblnewsletter').removeClassName('chked'); } })
• Qaisar Satti: you are mixing the jquery and prototype.
• AKSHAYA KUMAR Satapathy: But it shows an error "TypeError: $$(...).removeClassName is not a function"
• AKSHAYA KUMAR Satapathy: please solve it