diff --git a/src/main.c b/src/main.c
index 20a488f..f040c08 100644
--- a/src/main.c
+++ b/src/main.c
@@ -35,8 +35,13 @@ int db_search(db_t *db, rec_t *sample, float tresh, match_t **matches)
   blk.start = 1;
   blk.records = blk_size;
 
-  if (db_rd_rec(db, sample) != 1)
+  if (db_rd_rec(db, sample) < 1)
     return -1;
+
+  if (!sample->data[0]) {
+    puts("Sample not exists");
+    return 0;
+  }
   /* TODO: expand matches */
 
   while (db_rd_blk(db, &blk) > 0) {
@@ -65,9 +70,14 @@ int rec_bitmap(db_t *db, rec_t *sample)
   assert(db      != NULL);
   assert(sample  != NULL);
 
-  if (db_rd_rec(db, sample) != 1)
+  if (db_rd_rec(db, sample) < 1)
     return -1;
 
+  if (!sample->data[0]) {
+    puts("Sample not exists");
+    return 0;
+  }
+
   for (i = 0; i < 16; i++) {
     row = *(((uint16_t *) sample->data) + i);
     for (j = 0; j < 16; j++) {
@@ -84,6 +94,7 @@ int main(int argc, char **argv)
 {
   db_t db;
   rec_t sample;
+  float tresh;
 
   if (argc < 3) {
     printf(
@@ -96,8 +107,8 @@ int main(int argc, char **argv)
 
   memset(&db,     0x0, sizeof(db_t));
   memset(&sample, 0x0, sizeof(rec_t));
-  sample.num = atoll(argv[2]);
 
+  sample.num = atoll(argv[2]);
   assert(sample.num > 0);
 
   if (db_open(&db, "test.db") == -1) {
@@ -105,11 +116,14 @@ int main(int argc, char **argv)
     exit(EXIT_FAILURE);
   }
 
-  if (strcmp(argv[1], "search") == 0)
-    db_search(&db, &sample, 0.15, NULL);
+  if (strcmp(argv[1], "search") == 0) {
+    tresh = (argc > 3) ? atof(argv[3]) : 0.15;
+    db_search(&db, &sample, tresh, NULL);
+  }
 
-  if (strcmp(argv[1], "bitmap") == 0)
+  if (strcmp(argv[1], "bitmap") == 0) {
     rec_bitmap(&db, &sample);
+  }
 
   db_close(&db);