function GenerateGuid() {
return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());
function S4() {
return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
}
}
Source:
The new site