NKGetUniqueIdentifier returns the unique identifier of the device based on hardware serial number.
NKGetUniqueIdentifier()
<a href="#" onClick="showGUID();">Show NKGetUniqueIdentifier</a>
When the link is clicked, the "showGUID" function is called & the unique identifier of the device is displayed:
function showGUID()
{
NKAlert("Unique Identifier", NKGetUnigueIdentifier());
}