Key

Checks whether the specified key is pressed.

Parameters:
• key: String — One of: 'backspace', 'enter', 'shift', 'control', 'option', 'pause', 'caps-lock', 'escape', 'space', 'end', 'home', 'left', 'up', 'right', 'down', 'delete', 'command'

Returns:
• Boolean — true if the key is pressed, false otherwise

Example — Whenever the user clicks, create a circle shaped path. If the 'a' key is pressed, fill it with red, otherwise fill it with blue:

function onMouseDown(event) {
	var path = new Path.Circle(event.point, 10);
	if(Key.isDown('a')) {
		path.fillColor = 'red';
	} else {
		path.fillColor = 'blue';
	}
}