Barack Obama's former classmates in Indonesia, where he spent part of his childhood, reacted with joy as the boy who once stood by their side in the school yearbook was elected as the first black US president.

"I remember in the class book, all students were writing down their goals and wishes. Some said they wanted to be lawyers, soldiers, pilot and doctors, but he was the one who said he wanted to be president," said Dewi Asmara, a former classmate.

"We never understood what was on his mind that day."