Indonesians do not generally use the Western naming practice of a given first name and a family last name. The majority of Indonesians do not have family names as the West would understand them but, such names as are given, are geographically and culturally specific. Hence, names such as Supomo, Soeprapto, etc. beginning with "Su, Soe" and ending with an "o" are usually Javanese. In general, Indonesian names fall into one of the following categories (in order of popularity):

A single name, such as Sukarno
Two (or more) names without a family name, such as Rudy Hartono
Two (or more) names with a family name such as Abdul Haris Nasution or Liem Swie King
Two (or more) names with a patronymic family name, such as Megawati Sukarnoputri

Indonesian naming system
Most Muslim Indonesians do not have family names. Usually, men and women have a given name and take the name of their father. Some married Indonesian women take the last/family name of their husband, but not all, and this name is usually added after their own 'last' name. Therefore, it is not uncommon for married couples to have different last/family names.

Naming also differs around the country, with many Javanese having only one name; Sumatrans have clan names instead of family names; and some Chinese Indonesians have Chinese-style names. It is interesting to note that Indonesian telephone directories names are listed under first/given names, not under family names.
Occasionally, the father's name will be used as the surname. This is considered unofficial, since it does not match what is on the birth certificate. Despite being different from the official name, this format sometimes appears on government documents.

source: wikipedia