Phone number is only limited to a singapore phone number

[qinboan]

Some contacts might come from overseas and do not have any phone number/have an overseas number.

The fact that a Singapore phone number is compulsory to enter might make it difficult to add any foreign contact into the contact list.

A good fix would be to warn the user if the phone number is not a Singapore phone number but still accept it. Do note that special characters should also be allowed for country code etc.