LPC2148 "Interrupt based UART1"

I am making a Mobile phone using lpc2148 and a GSM modem SIM900.
i have the code for uart1 sending n receiving data. but it does not have interrupt based read function.
i want interrupt based uart1 read function.
here it is my code.

#include<lpc214x.h>

void Uart1Init (void)                       // Initialize Serial Interface
{
        PINSEL0 |= 0x00050000;           //Enable RxD1 and TxD1
    U1LCR = 0x83;                   // 8 bits, no Parity, 1 Stop bit
    U1DLL = 97;                     // 9600 Baud Rate @ 15MHz VPB Clock
    U1LCR = 0x03;                                       // DLAB = 0

}

void Uart1PutCh (unsigned char ch)   // Write character to Serial Port
{
        U1THR = ch;
        while (!(U1LSR & 0x20));
}

unsigned char Uart1GetCh (void)                 // Read character from Serial Port
{
  while (!(U1LSR & 0x01));
  return (U1RBR);
}


void  Uart1PutS(unsigned char *str)      //A function to send a string on UART1
{
   while(*str)
   {
      Uart1PutCh(*str++);
   }
}

int main(void)
{

}