diff --git a/src/userprog/syscall.c b/src/userprog/syscall.c
index d1927a96c08078cb069c98169b72b94d058c7bc8..e04ff992b09515a2a7c41ae8bf0228383741483d 100644
--- a/src/userprog/syscall.c
+++ b/src/userprog/syscall.c
@@ -18,11 +18,11 @@ syscall_handler (struct intr_frame *f UNUSED)
 {
   printf ("system call!\n");
   int syscall_nr=-1;
-  switch(sysCall) {
+  switch(syscall_nr) {
 	  case SYS_HALT:{
 		  printf ("system call, halt\n");
       shutdown_power_off();
 		  break;
-		  }
+    }
   thread_exit ();
 }