javaScritpt generates identification string

function generateUUID() {
		var d = new Date().getTime();
		var uuid = 'xxxxxxxxxxxx4xxxyxxxxxxxxxxxxxxx'.replace(/[xy]/g,
				function(c) {
					var r = (d + Math.random() * 16) % 16 | 0;
					d = Math.floor(d / 16);
					return (c == 'x' ? r : (r & 0x3 | 0x8)).toString(16);
				});
		return uuid;
	};