function check() {
    	var checks = document.getElementById('checkboxes').getElementsByTagName('input');
    	var status = (document.getElementById('checkall').checked == 1) ? true : false;
        for(var x = 0; x < checks.length; x++) {
        	checks[x].checked = status;
        }        
    }

Javascript - Check All/Uncheck All checkbox function

javascript

JavaScript