unresolved symbol Problem

[lina_zhao7]

 
 I write a simple program ,it works wrong!!!
program:
#include <linux/module.h>
#include <linux/wait.h>
#include <linux/init.h>
#include <linux/sched.h>
MODULE_LICENSE("GPL");
 
static int tms9914_init_module(void)
{
 wait_queue_head_t wait;
 int con=1;
 init_waitqueue_head(&wait);
 if(wait_event_timeout(wait,con,100)==0)
  {
   printk("gpib command wait interrupted\n");
   
  }
 return 0;
}
static void tms9914_exit_module(void)
{
}
module_init( tms9914_init_module );
module_exit( tms9914_exit_module );

problem:unresolved symbol wait_event_timeout 
 
why???????????