create a guid using javascript

guid.js

function guid() {
	var strguid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
		var r = Math.random()*16|0, v = c === 'x' ? r : (r&0x3|0x8);
		return v.toString(16);
	});
	return strguid;
}