diff --git a/user/app_singlepageheap.c b/user/app_singlepageheap.c
index 61f8ba1..8c302fc 100644
--- a/user/app_singlepageheap.c
+++ b/user/app_singlepageheap.c
@@ -4,11 +4,19 @@
  */
 
 #include "user_lib.h"
-#include "util/types.h"
-#include "util/string.h"
+//#include "util/string.h"
+
+typedef unsigned long long uint64;
+
+char* strcpy(char* dest, const char* src) {
+  char* d = dest;
+  while ((*d++ = *src++))
+    ;
+  return dest;
+}
 int main(void) {
   
-  char str[20] = "hello world.";
+  char str[20] = "hello, world!!!";
   char *m = (char *)better_malloc(100);
   char *p = (char *)better_malloc(50);
   if((uint64)p - (uint64)m > 512 ){
@@ -19,6 +27,16 @@ int main(void) {
 
   strcpy(p,str);
   printu("%s\n",p);
+  char *n = (char *)better_malloc(50);
+  
+  if(m != n)
+  {
+    printu("your malloc is not complete.\n");
+    exit(-1);
+  }
+//  else{
+//    printu("0x%lx 0x%lx\n", m, n);
+//  }
   exit(0);
   return 0;
 }