code for communication between SIM300 GSM module and MSP430G2553 controller

hi,

I want to send AT commands to SIM300 GSM Module with the code i have written for MSP430G2553 controller.i am using hyperterminal .the problem i am getting is i couldn't able to sent it.my code

#include <msp430.h>
#include <msp430g2553.h>
#include <string.h>

#define LED BIT0
#define RXD BIT1
#define TXD BIT2

void uart_init(void);
unsigned char uart_getc();
void uart_gets();
void uart_putc(unsigned char c);
void uart_puts(char *str);
char arr[32];

volatile unsigned int tx_flag; //Mailbox Flag for the tx_char.
volatile unsigned char tx_char; //This char is the most current char to go into the UART

volatile unsigned int rx_flag; //Mailbox Flag for the rx_char.
volatile unsigned char rx_char; //This char is the most current char to come out of the UART

//------------------------------------------------------------------------------------------------
void uart_init(void)
{
P1SEL = RXD + TXD; //Setup the I/O
P1SEL2 = RXD + TXD;

P1DIR |= LED; //P1.0 red LED. Toggle when char received.
P1OUT |= LED; //LED off

UCA0CTL1 |= UCSSEL_2; //SMCLK //8,000,000Hz, 9600Baud, UCBRx=52, UCBRSx=0, UCBRFx=1
UCA0BR0 = 52; //8MHz, OSC16, 9600
UCA0BR1 = 0; //((8MHz/9600)/16) = 52.08333
UCA0MCTL = 0x10|UCOS16; //UCBRFx=1,UCBRSx=0, UCOS16=1
UCA0CTL1 &= ~UCSWRST; //USCI state machine
IE2 |= UCA0RXIE; //Enable USCI_A0 RX interrupt

rx_flag = 0; //Set rx_flag to 0
tx_flag = 0; //Set tx_flag to 0

}
//-------------------------------------------------------------------------------------------------------
unsigned char uart_getc() //Waits for a valid char from the UART
{
while (rx_flag == 0); //Wait for rx_flag to be set
rx_flag = 0; //ACK rx_flag
return rx_char;
}

void uart_gets(char* Array, int length)
{
unsigned int i = 0;
while((i < length)) //Grab data till the array fills
{
Array[i] = uart_getc();
if(Array[i] == '\r') //If we receive a \r the master wants to end
{
for( ; i < length ; i++) //fill the rest of the string with \0 null. Overwrites the \r with \0
{
Array[i] = '\0';
}
break;
}
i++;
}

}
//------------------------------------------------------------------------------------------------------------
void uart_putc(unsigned char c)
{
tx_char = c; //Put the char into the tx_char
IE2 |= UCA0TXIE; //Enable USCI_A0 TX interrupt
while(tx_flag == 1); //Have to wait for the TX buffer
tx_flag = 1; //Reset the tx_flag
}

void uart_puts(char *str) //Sends a String to the UART.
{
while(*str)
uart_putc(*str++); //Advance though string till end
}
//-----------------------------------------------------------------------------------------------------------

#pragma vector=USCIAB0TX_VECTOR//UART TX USCI Interrupt
__interrupt void TX_ISR(void)
{
UCA0TXBUF = tx_char; //Copy char to the TX Buffer
tx_flag = 0; //ACK the tx_flag
IE2 &= ~UCA0TXIE; //Turn off the interrupt to save CPU
}

#pragma vector=USCIAB0RX_VECTOR//UART RX USCI Interrupt. This triggers when the USCI receives a char.
__interrupt void RX_ISR(void)
{
rx_char = UCA0RXBUF; //Copy from RX buffer, in doing so we ACK the interrupt as well
rx_flag = 1; //Set the rx_flag to 1
P1OUT ^= LED; //Notify that we received a char by toggling LED
}

//-------------------------------------------------------------------------------------------------------------
void gsm()
{
uart_gets(arr,sizeof(arr));
if((strcmp("Call Ready",arr))==0)
{
uart_puts((char *)"AT"); // COMMAND FOR INITIALIZING GSM
uart_putc(0x0A); //ENTER
uart_putc(0x0D);//CARRIAGE RETURN
__delay_cycles(100000);
}
else
uart_puts((char *)"call cannot be connected");

uart_gets(arr,sizeof(arr));
if((strcmp("OK",arr))==0)
{
uart_puts((char *)"ATD9028901369;"); //COMMUNICATION
uart_putc(0x0A); //ENTER
uart_putc(0x0D); //CARRIAGE RETURN
}
else
uart_puts((char *)"Enter valid number");

}
//-------------------------------------------------------------------------------------------------------------
int main(void)
{

WDTCTL = WDTPW + WDTHOLD; // STOP WATCHDOG TIMER
BCSCTL1 = CALBC1_8MHZ; // MAKE THE FREQUNCY AS PER THE LAUNCHPAD 8MHZ
DCOCTL = CALDCO_8MHZ;

uart_init(); // CALL THE UART INIT FUNCTION WHICH IS AVAILAIBLE IN THE FILE
__enable_interrupt(); //enable interrupt
//__delay_cycles(100000);
gsm();
while(1);

}