fg: no job control error during signal handling

[can-mohan]

Hi,

in below code snippet i am trying to resume again forground process by issuing fg %1 in code but still it doesn't work.
usually after issuing fg %1 from command prompt it should alwaysstart first suspended process but same is not happening
and i am getting error like ; sh: line 0: fg: no job control.

#include<stdio.h>
#include<signal.h>
#include<unistd.h>

void sig_handler(int signo)
{
  if (signo == SIGTSTP)
    printf("received SIGINT \n");
   system("fg %1");
   printf("process will be resumed again");
}

int main(void)
{
  if (signal(SIGTSTP, sig_handler) == SIG_ERR)
  printf("\ncan't catch SIGSTP\n");
  // A long long wait so that we can easily issue a signal to this process
   for(;;){  }
   //printf("resuming the process");

}