diff --git a/binding/nodejs/ip2region.js b/binding/nodejs/ip2region.js
index de1ce42..873b06f 100644
--- a/binding/nodejs/ip2region.js
+++ b/binding/nodejs/ip2region.js
@@ -11,40 +11,53 @@ function Ip2region(db_path)
 {
     var fs   = require('fs');
     var ipbase = [16777216, 65536, 256, 1]; // for ip2long
-    var ip2r = {};
-    ip2r.db_file_path   = null;
-    ip2r.db_fd          = null;
+    var db_file_path   = null;
+    var db_fd          = null;
 
     // db file check
     if (typeof(db_path) == "undefined" || fs.exists(db_path) ) {
         throw("[ip2region] db file not exists : " + db_path);
     }
     
-    ip2r.db_file_path = db_path; 
+    db_file_path = db_path; 
 
     try {
-        ip2r.db_fd = fs.openSync(ip2r.db_file_path, 'r');
+        db_fd = fs.openSync(db_file_path, 'r');
     } catch(e) {
-        throw("[ip2region] Can not open ip2region.db file , path : " + ip2r.db_file_path);
+        throw("[ip2region] Can not open ip2region.db file , path : " + db_file_path);
     }
 
+    var totalBlocks     = 0;
+    var firstIndexPtr   = 0;
+    var lastIndexPtr    = 0;
+    var superBlock      = new Buffer(8);
 
     this.binarySearch = function(ip)
     {
-        var buffer = new Buffer(8);
-        fs.readSync(ip2r.db_fd, buffer, 0, 8, 0);
+        if (typeof(ip) == 'string') ip = ip2long(ip);
 
-        console.log(getLong(buffer, 0));
-        console.log(getLong(buffer, 4));
+        // init basic search environment
+        if (totalBlocks == 0) {
+            fs.readSync(ip2r.db_fd, superBlock, 0, 8, 0);
+            firstIndexPtr = getLong(superBlock, 0);
+            lastIndexPtr  = getLong(superBlock, 4);
+        }
+
+        // search
 
         return ip2long(ip);
     }
 
+
     this.btreeSearch = function(ip) 
     {
         return ip2long(ip);
     }
 
+
+    /**
+     * convert ip to long (xxx.xxx.xxx.xxx to a integer)
+     * */
     function ip2long(ip)
     {
         var val = 0;
@@ -55,11 +68,15 @@ function Ip2region(db_path)
         return val;
     }
 
+
+    /**
+     * get long value from buffer with specified offset
+     * */
     function getLong(buffer, offset) 
     {
         return  (   
-            (buffer[offset] & 0x000000FF ) | 
-            ((buffer[offset + 1] << 8)  & 0x0000FF00) | 
+            (buffer[offset] & 0x000000FF) | 
+            ((buffer[offset + 1] <<  8) & 0x0000FF00) | 
             ((buffer[offset + 2] << 16) & 0x00FF0000) |
             ((buffer[offset + 3] << 24) & 0xFF000000)
         );
diff --git a/binding/nodejs/test.js b/binding/nodejs/test.js
index 7054c58..46643cb 100644
--- a/binding/nodejs/test.js
+++ b/binding/nodejs/test.js
@@ -5,4 +5,4 @@
 var Ip2region = require('./ip2region');
 var ip2region = new Ip2region('../../data/ip2region.db'); 
 
-console.log(ip2region.binarySearch("114.114.114.114"));
+console.log(ip2region.binarySearch("255.255.255.255"));