how to handle multiple interrupts in GCC using LPC2138

hi all,
can any body plz tell me how to handle more than one interrupts
simultaneously
in GCC .
single interrupts are working separately when I changed in startup.s
file like below:
************************************************************************ 
*******
# Exception Vectors
#  Mapped to Address 0.
#  Absolute addressing mode must be used.
#  Dummy Handlers are implemented as infinite loops which can be
modified.

Vectors:        LDR     PC, Reset_Addr
                LDR     PC, Undef_Addr
                LDR     PC, SWI_Addr
                LDR     PC, PAbt_Addr
                LDR     PC, DAbt_Addr
                NOP                            /* Reserved Vector */

    LDR     PC, IRQ_Addr
                LDR     PC, FIQ_Addr

Reset_Addr:     .word   Reset_Handler
Undef_Addr:     .word   Undef_Handler
SWI_Addr:       .word   SWI_Handler
PAbt_Addr:      .word   PAbt_Handler
DAbt_Addr:      .word   DAbt_Handler
                .word   0                      /* Reserved Address */

IRQ_Addr:       .word   uart0 /* uart0 is the service routine function
which I placed here  */
FIQ_Addr:  .word   FIQ_Handler

Undef_Handler:  B       Undef_Handler
SWI_Handler:    B       SWI_Handler
PAbt_Handler:   B       PAbt_Handler
DAbt_Handler:   B       DAbt_Handler

IRQ_Handler:    B      uart0  /* uart0 is the service routine function
which I placed here  */

FIQ_Handler:    B   FIQ_Handler
************************************************************************ 
*******
prototype defined is :
void uart0(void) _attribute_ ((interrupt ("IRQ")));
I hav alredy posted a mail earlier but not received any response yet.

now plz tell me how to handle multiple interrupts?
thanks.