yeohsheng WROTE:anyways thx everyone who tried to help. i have succeed.
i found out the problem is my xbee starter kit. the rx tx output pin seems to have problem. so i take out the xbee then connect using breadboard, then it works like charm. xD
one more things, for RX and TX there is no need to use 100ohms. it works in my case
now i move on to API mode. as i need the mesh connection
Well done. Not connect 100 ohm sure working, but maybe it's reduce lifespan of the xbee module because giving 5V signal into 3V device.