Cannot send message?

Hi all,

I unable send out message ???

RDY

+CFUN: 1

+CPIN: READY

GPS Ready

Call Ready
AT

OK
AT+CSQ

AT

OK
AT+CSQ=?

+CSQ: (0-31,99),(0-7,99)

OK
AT+CSQ

+CSQ: 14,0

OK
AT

OK
at+CMGF=1

OK

AT+CMGS="0xxxx093"

> HI.
ERROR
AT+CSQ

+CSQ: 14,0

OK
AT+CSQ=?

+CSQ: (0-31,99),(0-7,99)

OK
AT+CMGS="01xxxx93"

> HI.
ERROR


May i ask what is the causes fro it? Is it possible causes by power supply as they powered by 350mA/7.5V

The code I used as wrote in Wiki
void setup()
{
  //Init the driver pins for GSM function
    pinMode(3,OUTPUT);
    pinMode(4,OUTPUT);
    pinMode(5,OUTPUT);
  //Output GSM Timing
    digitalWrite(5,HIGH);
    delay(1500);
    digitalWrite(5,LOW);
}
void loop()   
{   
    // Use these commands instead of the hardware switch 'UART select' in order to enable each mode
    // If you want to use both GMS and GPS. enable the required one in your code and disable the other one for each access.
    digitalWrite(3,LOW);//enable GSM TX?RX
    digitalWrite(4,HIGH);//disable GPS TX?RX
}

Thanks reply.=)
JJ