Untitled

<!doctype html>
	<head>
		<title>JavaScript Exercise 1</title>
		<script type="text/javascript">
			function checkall(){
				var checkboxes_array = document.getElementsByTagName('input');
				for (var k=0; k<checkboxes_array.length;k++){
					checkboxes_array[k].checked = true;
				}
				console.log('checkall called');
			}

			function checknone(){
				var checkboxes_array = document.getElementsByTagName('input');
				for (var k=0; k<checkboxes_array.length;k++){
					checkboxes_array[k].checked = false;
				}
				console.log('checknone called');
			}
		</script>
	</head>
	<body>
		<label>Red</label>
		<input type='checkbox' name='red' value='red'/><br/>
		<label>Green</label>
		<input type='checkbox' name='green' value='green'/><br/>
		<label>Yellow</label>
		<input type='checkbox' name='yellow' value='yellow'/><br/>
		<label>White</label>
		<input type='checkbox' name='white' value='white'/><br/>
		<label>Black</label>
		<input type='checkbox' name='black' value='black'/><br/><br/>

		<label>Check All</label>
		<input type='checkbox' name='black' value='black' onclick='checkall()'/><br/>

		<label>Check None</label>
		<input type='checkbox' name='black' value='black' onclick='checknone()'/><br/>

	</body>
</html>