Question

There is a CheckBox & Button, I want to click on Button to checked & unchecked the checkBox without touching the checkBox. How to do that ???

<input type = "checkbox"  id = "check" />
<input type = "button"  id = "buttonId" />

<script type = "text/javascript">
   $(function() {
       $("#buttonId").click( function() { 
            if( $("#check").is_NOT_CHECKED) {
                 CHECKED_CheckBox;
                        }         else 
                     if($("#check").is_CHECKED) {
                           UnCHECKED_CheckBox;
                           }    
                    });
   </script>

Answer 1

How about

$("#buttonId").click( function() {
    var checkbox = $("#check")[0];

    checkbox.checked = !checkbox.checked; // invert its checked status

});

demo at http://jsfiddle.net/gaby/czRkv/