关于线程的创建，怎么修改这个代码呀？

#include <stdio.h>
#include<stdlib.h>
#include <unistd.h>
#include<>
void *thread(void arg)
{
pthread_t newthid;
newthid= pthread_self();
printf("this is a new thread,thread ID=?\n",newthid);
return NULL ;
}
int main(void)
{
pthread_t thid;
printf(" main thread,lD is ?n",pthread_self());
if(pthread_create (&?,?(void)?,?)!=0)

{
printf("thread creation failed,n");
exit(-1);
}
printf(" new thread:");
sleep(1);
exit(0);
}