diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d7e6459
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+composer.lock
+/vendor
+/.buildpath
+/.project
+/.settings
diff --git a/README.md b/README.md
index 247e288..72e25b4 100644
--- a/README.md
+++ b/README.md
@@ -22,4 +22,27 @@ if ($domain->isAvailable()) {
     echo "Domain is registered\n";
 }
 
-```
\ No newline at end of file
+```
+
+A more complete example:
+
+```php
+
+<?php
+require_once __DIR__.'/../vendor/autoload.php';
+
+$sld = 'nabi.ir';
+
+try {
+	$domain = new Phois\Whois\Whois($sld);
+} catch (InvalidArgumentException $e) {
+	die($e->getMessage()."\n");
+}
+
+if ($domain->isAvailable()) {
+	echo "Domain is available\n";
+} else {
+	echo "Domain is registered\n";
+}
+
+```
diff --git a/examples/usage-example2.php b/examples/usage-example2.php
new file mode 100644
index 0000000..b1c3256
--- /dev/null
+++ b/examples/usage-example2.php
@@ -0,0 +1,16 @@
+<?php
+require_once __DIR__.'/../vendor/autoload.php';
+
+$sld = 'nabi.ir';
+
+try {
+	$domain = new Phois\Whois\Whois($sld);
+} catch (InvalidArgumentException $e) {
+	die($e->getMessage()."\n");
+}
+
+if ($domain->isAvailable()) {
+	echo "Domain is available\n";
+} else {
+	echo "Domain is registered\n";
+}
diff --git a/src/Phois/Whois/Whois.php b/src/Phois/Whois/Whois.php
index 2740c4f..ae9db26 100644
--- a/src/Phois/Whois/Whois.php
+++ b/src/Phois/Whois/Whois.php
@@ -11,6 +11,8 @@ class Whois
     private $subDomain;
 
     private $servers;
+    
+    private $whoisInfo; 
 
     /**
      * @param string $domain full domain name (without trailing dot)
@@ -29,10 +31,19 @@ public function __construct($domain)
             throw new \InvalidArgumentException("Invalid $domain syntax");
         // setup whois servers array from json file
         $this->servers = json_decode(file_get_contents( __DIR__.'/whois.servers.json' ), true);
+        
+        if (!$this->isValid())
+        	throw new \InvalidArgumentException("Domain name isn't valid!");
     }
-
+    
+    /**
+     * @param string, domain whois information
+     */
     public function info()
     {
+        if ($this->whoisInfo != '')
+            return $this->whoisInfo;
+
         if ($this->isValid()) {
             $whois_server = $this->servers[$this->TLDs][0];
 
@@ -116,12 +127,13 @@ public function info()
                 $string_encoding = mb_detect_encoding($string, "UTF-8, ISO-8859-1, ISO-8859-15", true);
                 $string_utf8 = mb_convert_encoding($string, "UTF-8", $string_encoding);
 
-                return htmlspecialchars($string_utf8, ENT_COMPAT, "UTF-8", true);
+                $this->whoisInfo = htmlspecialchars($string_utf8, ENT_COMPAT, "UTF-8", true);
+                return $this->whoisInfo;
             } else {
                 return "No whois server for this tld in list!";
             }
         } else {
-            return "Domainname isn't valid!";
+            return "Domain name isn't valid!";
         }
     }
 
@@ -153,10 +165,16 @@ public function getSubDomain()
     {
         return $this->subDomain;
     }
-
+    
+	/**
+     * @return boolean, true for domain avaliable, false for domain registered
+     */
     public function isAvailable()
     {
-        $whois_string = $this->info();
+        if ($this->whoisInfo == '')
+            $whois_string = $this->info();
+        else 
+        	$whois_string = $this->whoisInfo;
         $not_found_string = '';
         if (isset($this->servers[$this->TLDs][1])) {
            $not_found_string = $this->servers[$this->TLDs][1];
diff --git a/src/Phois/Whois/whois.servers.json b/src/Phois/Whois/whois.servers.json
index 50a42a4..987502c 100644
--- a/src/Phois/Whois/whois.servers.json
+++ b/src/Phois/Whois/whois.servers.json
@@ -1491,6 +1491,34 @@
         "whois.nic.ir",
         "no entries found"
     ],
+    "co.ir": [
+        "whois.nic.ir",
+        "no entries found"
+    ],
+    "ac.ir": [
+        "whois.nic.ir",
+        "no entries found"
+    ],
+    "sch.ir": [
+        "whois.nic.ir",
+        "no entries found"
+    ],
+    "id.ir": [
+        "whois.nic.ir",
+        "no entries found"
+    ],
+    "gov.ir": [
+        "whois.nic.ir",
+        "no entries found"
+    ],
+    "org.ir": [
+        "whois.nic.ir",
+        "no entries found"
+    ],
+    "net.ir": [
+        "whois.nic.ir",
+        "no entries found"
+    ],
     "ru": [
         "whois.ripn.net",
         "No entries found"