ARM RTOS Problem... Help

Hi friends
I wrote the code for the ARM RTOS(no warnings and no errors)

and NO OUTPUT.. so please suggest me where i am going wrong

i am doing 2 task
task1:buzzer_operation();//turning ON and OFF the buzzer
task2:ADC_operation(); //reading continuously the Analog input and displaying on the LCD

i had checked these two programs individually , they ARE working

could you please tell me where i am going wrong in this code
my code is here

#include<lpc214x.h>
#include"adc.h"
#include"buzzer.h"
/* Include type and function declarations for RTX */
#include <RTL.h>
#include <RTX_Config.h>
/* id1, id2 will contain task identifications at run-time */
OS_TID id1, id2;

/* Forward reference. */
__task void tsk1 (void);
__task void tsk2 (void);

__task void tsk1 (void) { /* Obtain own system task identification number */ id1 = os_tsk_self (); /* Assign system identification number of task2 to id2 */ id2 = os_tsk_create (tsk2, 0); for (;;) { /* do-this */ buzzer(); /* Indicate to task2 completion of do-this */ os_evt_set (0x0004, id2); /* Wait for completion of do-that (0xffff means no time-out)*/ os_evt_wait_or (0x0004, 0xffff); /* Wait now for 50 ms */ os_dly_wait (5); }
}

__task void tsk2 (void)
{ for (;;) { ADC(); /* Wait for completion of do-this (0xffff means no time-out) */ os_evt_wait_or (0x0004, 0xffff); /* do-that */ /* Pause for 20 ms until signaling event to task1 */ os_dly_wait (2); /* Indicate to task1 completion of do-that */ os_evt_set (0x0004, id1); }
}

int main (void)
{ os_sys_init (tsk1); return 0;
}