Create a contact and add it to Global Address List in Outlook 2010

Hi,

I'm wondering if there is a way I can create a contact and add it to the Global Address List in Outlook 2010’s Address Book. In Outlook 2010, I went to Address Book > File > New Entry, under ‘Select the entry type’, I selected New Contact, under ‘Put this entry in’ I selected Global Address List; but it says ‘You cannot create entries for this address book’.   

Thanks,

Chew