Javascript rfc4122 version 4 compliant solution oneliner

gistfile1.txt

//from: http://stackoverflow.com/questions/105034/create-guid-uuid-in-javascript
'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);
});