SIM800 SMS Encoding problem

Hi,
IM using SIM800L to send data. i just figured how to send data through gprs but i have trouble with sending sms .
when i send message on the other side i get nothing or some kind of Chinese characters (like this: 瑨楳⁩猠瑥獴⁳浳) .
here is my code:

sim800.printn("AT+CMGF=1");    //return ok
delay(100);
sim800.println("AT + CMGS = \"50002333126507\""); return >
delay(100);
sim800.print("Hello, world. This is a text message from an Arduino Uno.");
sim800.write(0x1A); 
sim800.write(0x0A);
delay(100);
sim800.println();

Also i tried AT+CSCS="GSM" and "IRA" before CMGS
any one knows whats wrong?