diff --git a/README.md b/README.md
index 21995de..076f7f5 100644
--- a/README.md
+++ b/README.md
@@ -85,7 +85,7 @@ enableLink         | **Optional.** Enable/disable graph with a rendered URL to t
 datasource         | **Required.** Type of the Grafana datasource (`influxdb`, `graphite` or `pnp`). Defaults to `influxdb`.
 defaultdashboard   | **Required.** Name of the default dashboard which will be shown for unconfigured graphs. **Important: `panelID` must be set to `1`!** Defaults to `icinga2-default`.
 defaultdashboardstore | **Optional.** Grafana backend (file or database). Defaults to `Database`.
-accessmode         | **Optional.** Controlls if module proxies all graphs or user loads graphs directly. Direct access speeds up page load, needs `auth.anonymous` enabled in Grafana. Defaults to `proxy`.
+accessmode         | **Optional.** Controls whether graphs are fetched with curl (`proxy`) or are embedded (`direct`). Direct access is faster and needs `auth.anonymous` enabled in Grafana. Defaults to `proxy`.
 
 
 Example:
diff --git a/library/Grafana/ProvidedHook/Grapher.php b/library/Grafana/ProvidedHook/Grapher.php
index 6f21ef6..cfd5d46 100644
--- a/library/Grafana/ProvidedHook/Grapher.php
+++ b/library/Grafana/ProvidedHook/Grapher.php
@@ -5,12 +5,14 @@
 use Icinga\Application\Icinga;
 use Icinga\Application\Config;
 use Icinga\Exception\ConfigurationError;
+use Exception;
 use Icinga\Application\Hook\GrapherHook;
 use Icinga\Module\Monitoring\Object\MonitoredObject;
 use Icinga\Module\Monitoring\Object\Host;
 use Icinga\Module\Monitoring\Object\Service;
 use Icinga\Web\Url;
 use Icinga\Web\View;
+use Icinga\Module\Grafana\Util;
 
 class Grapher extends GrapherHook
 {
@@ -83,12 +85,12 @@ protected function init()
         {
             if($this->password != null)
             {
-                $this->auth = $this->username.":".$this->password."@";
+                $this->auth = $this->username.":".$this->password;
             }
             else
-           {
-                $this->auth = $this->username."@";
-           }
+            {
+                $this->auth = $this->username;
+            }
         }
         else
         {
@@ -177,22 +179,35 @@ private function getPreviewImage($serviceName, $hostName)
 
             // fetch image with curl
             $curl_handle = curl_init();
-            curl_setopt($curl_handle,CURLOPT_URL,$pngUrl);
-            curl_setopt($curl_handle,CURLOPT_CONNECTTIMEOUT,2);
-            curl_setopt($curl_handle,CURLOPT_RETURNTRANSFER,true);
-            curl_setopt($curl_handle,CURLOPT_SSL_VERIFYPEER,false);
-            curl_setopt($curl_handle,CURLOPT_TIMEOUT,5);
-            curl_setopt($curl_handle, CURLOPT_USERPWD, "$this->auth");
-	    curl_setopt($curl_handle, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
-            $imgBinary = curl_exec($curl_handle);
-            if(curl_error($curl_handle))
-            {
-                return 'Graph currently unavailable: :' . curl_error($curl_handle);
+            $curl_opts = array(
+                CURLOPT_URL => $pngUrl,
+                CURLOPT_CONNECTTIMEOUT => 2,
+                CURLOPT_RETURNTRANSFER => true,
+                CURLOPT_SSL_VERIFYPEER => false, //TODO: config option
+                CURLOPT_TIMEOUT => 5, //TODO: config option
+                CURLOPT_USERPWD => "$this->auth",
+                CURLOPT_HTTPAUTH, CURLAUTH_ANY
+            );
+
+            curl_setopt_array($curl_handle, $curl_opts);
+
+            $res = curl_exec($curl_handle);
+
+            if ($res === false) {
+                return "<b>Graph currently unavailable: Curl error: ' . curl_error($curl_handle)</b>";
             }
-            curl_close($curl_handle);
 
+            $statusCode = curl_getinfo($curl_handle, CURLINFO_HTTP_CODE);
+
+            if ($statusCode > 299) {
+                $error = @json_decode($res);
+		return "<b>Cannot fetch Grafana graph: ". Util::httpStatusCodeToString($statusCode) .
+                       " ($statusCode)</b>: " . (property_exists($error, 'message') ? $error->message : "");
+            }
+
+            curl_close($curl_handle);
 
-            $img = 'data:image/png;base64,'.base64_encode($imgBinary);
+            $img = 'data:image/png;base64,'.base64_encode($res);
             $imghtml = '<img src="%s" alt="%s" width="%d" height="%d" />';
             return sprintf(
                 $imghtml,
diff --git a/library/Grafana/Util.php b/library/Grafana/Util.php
new file mode 100644
index 0000000..c4c5778
--- /dev/null
+++ b/library/Grafana/Util.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace Icinga\Module\Grafana;
+
+class Util
+{
+
+    public static function httpStatusCodetoString($code = 0)
+    {
+        $statuscodes = array(
+            '100' => 'Continue',
+            '101' => 'Switching Protocols',
+            '200' => 'OK',
+            '201' => 'Created',
+            '202' => 'Accepted',
+            '203' => 'Non-Authoritative Information',
+            '204' => 'No Content',
+            '205' => 'Reset Content',
+            '206' => 'Partial Content',
+            '300' => 'Multiple Choices',
+            '302' => 'Found',
+            '303' => 'See Other',
+            '304' => 'Not Modified',
+            '305' => 'Use Proxy',
+            '400' => 'Bad Request',
+            '401' => 'Unauthorized',
+            '402' => 'Payment Required',
+            '403' => 'Forbidden',
+            '404' => 'Not Found',
+            '405' => 'Method Not Allowed',
+            '406' => 'Not Acceptable',
+            '407' => 'Proxy Authentication Required',
+            '408' => 'Request Timeout',
+            '409' => 'Conflict',
+            '410' => 'Gone',
+            '411' => 'Length Required',
+            '412' => 'Precondition Failed',
+            '413' => 'Request Entity Too Large',
+            '414' => 'Request-URI Too Long',
+            '415' => 'Unsupported Media Type',
+            '416' => 'Requested Range Not Satisfiable',
+            '417' => 'Expectation Failed',
+            '500' => 'Internal Server Error',
+            '501' => 'Not Implemented',
+            '502' => 'Bad Gateway',
+            '503' => 'Service Unavailable',
+            '504' => 'Gateway Timeout',
+            '505' => 'HTTP Version Not Supported'
+        );
+        
+        $code = (string)$code;
+        
+        if(array_key_exists($code, $statuscodes)) {
+            return $statuscodes[$code];
+        } else {
+            return $code;
+        }
+    }
+}