Create Child Using Fork in C program | Operating System

Create a process. Fork to create a child process. Display pid, ppid, gid and uid in
the child process and display pid, gid and uid for the parent process

This is small program to create process using fork() method as after call fork() it will return -1 if child creation fail,return 0 if child creation successful ,return child pid to  parent.
void  main()
pid_t pid;
           case -1:printf("Child Creation Fail..!!");
           case 0: 
                printf("I AM THE CHILD PROCESSn");
printf("The Child process id is %d ppid is %d gid is %d uid id %d n",getpid(),getppid(),getgid(),getuid());

default: printf("I AM THE PARENT PROCESSn");
printf("The Parent process id is %d gid %d uid %d n",getpid(),getgid(),getuid());