Communication UART2/3

Hi all !
Now I am making a communication between two LPC2368 chips (one on MCB2300 Ver3.1 board, one on LPC236x_DevMaster Board). On MCB2300 board I use UART2 as Receiver, the UART3 on remain board I use as Transmitter. I use two difference port because now I test the both port on MCB2300 board only. I run code and saw : * These is interrupt at Transmitter, but no signal come-out TXD3 pin. * Nothing on RXD2.

Below is my code.

int main (void)
{
 for ( i = 0; i < BUFSIZE; i++ )// Initialize TX value
  {
    Receive_UART2_Buffer[i] = 0;
    Transmit_UART3_Buffer[i] = i;
  }
    lcd_init();
    lcd_clear();

  UARTInit(2, 115200);/* baud rate setting for UART2*/
  UARTInit(3, 115200);/* baud rate setting for UART3*/

  while (1)
  {
 Check_TEMT = (U3LSR >> 6)&0x01;
 //Checks the UnTHR and UnTSR in UART3 are empty or not

 if ( (Check_TEMT)&(Int_Empty_TX_Done))
//The UnTHR and UnTSR are empty and UART3_ISR completed
    {
      j++;
      Int_Empty_TX_Done = 0 ; // Un-set global flag

      UART3_Send((BYTE *)Transmit_UART3_Buffer, 1 );
    // Send 1byte when both thUnTHR and UnTSR are empty
    }

in UART_int() function I turned on already PCONP register and PINSEL0 for UART2/3 function

    PCONP |= (0x01<<25);  // Turn on UART3 power
    PINSEL0 |= (0x02<<0);    // Set P0.0 as TXD3
    PINSEL0 |= (0x02<<2);    // Set P0.1 as RXD3

    PCONP |= (0x01<<24);  // Turn on UART2 power
    PINSEL0 |= (0x01<<22);   // Set P0.11 as RXD2
    PINSEL0 |= (0x01<<20);    // Set P0.10 as TXD2

and in ISR_function

void UART3Handler (void) __irq
{
  U3FCR |= (0x01<<2) ; // TX FIFO Reset
  Int_Empty_TX_Done = 1 ;

  VICVectAddr = 0;      /* Acknowledge Interrupt */
}

I printed the value of "j" on LCD, I saw it is increased, meaning the UART3 ( Transmitter ) interrupted. Anybody can show me where my mistake ? And help me slove it. Thanks everybody.