webkitpdf.php

diff --git a/webkitpdf.php b/webkitpdf.php
index b450c2d..5715f3c 100644 (file)
--- a/webkitpdf.php
+++ b/webkitpdf.php
@@ -25,11 +25,21 @@ class WebkitPdf
     function WebkitPdf()
     {
         if (empty($_REQUEST['url'])) {
-            $this->h404();
+            $this->h404("missing url");
         }
         
         require_once 'System.php';
-        $xvfb = 
+        
+        $xvfb = System::which('xvfb');
+        if (empty($xvfb)) {
+            $this->h404("missing xvfb");
+        }
+        
+        $xvfb = System::which('webkitpdf');
+        if (empty($xvfb)) {
+            $this->h404("missing webkitpdf (compile it..)");
+        }
+        
         
     }