tect-if-multiple-keys-are-pressed-at-once-using-javascript
*/	
var map = {};
onkeydown = onkeyup = function(e){
    e = e || event; // to deal with IE
    map[e.keyCode] = e.type == 'keydown';
	
	if(map[87] || map[38]){ // ArrowUp / W
		leftVector.y = -200;
	}
	if(map[83] || map[40]){ // ArrowDown / S
		leftVector.y = 200;
	}
	if(map[65] || map[37]){ // ArrowLeft / A
		leftVector.x = -200;
	}
	if(map[68] || map[39]){ // ArrowRight / D
		leftVector.x = 200;
	}
	if(map[81]){ // Q
		rightVector.x = -255;
	}
	i