diff --git a/config.toml b/config.toml
index 6cf880f..89a17a3 100644
--- a/config.toml
+++ b/config.toml
@@ -1,4 +1,4 @@
-baseurl = "http://pmpc.mehl.mx/"
+baseurl = "/"
 title = "Public Money, Public Code"
 theme = "hugo-creative-theme"
 DefaultContentLanguage = "en"
diff --git a/static/cgi-bin/sign.php b/static/cgi-bin/sign.php
index 62a2de0..6de880b 100644
--- a/static/cgi-bin/sign.php
+++ b/static/cgi-bin/sign.php
@@ -1,3 +1,69 @@
 <?php
 
+$error = 0;  // error status
+
+// Database path
+$db = "../userdata/signatures.json";
+
+// Get info from form
+$name = $_GET['name'];
+$email = $_GET['email'];
+$country = $_GET['country'];
+$zip = $_GET['zip'];
+$perm = $_GET['permission'];
+
+// Validate input
+
+// Create a random string for email verification
+$code = rand(1000000000,9999999999) . uniqid();
+
+// Read database
+$file = file_get_contents($db, true);
+$data = json_decode($file, true);
+unset($file);
+
+// Test whether email is a duplicate
+$total = count($data);
+for ($row = 0; $row <= $total; $row++) {
+  if ($email === $data[$row]['email']) {
+    echo "email $email already exists!";
+    $error = 1;
+    break 1;
+  }
+}
+
+if ($error === 0) {   // only make entry if no error happened
+  // Take sequential ID
+  $id = $total;
+
+  // Append new signature to array
+  $newsig = array("id" => $id,
+                  "name" => $name, 
+                  "email" => $email,
+                  "country" => $country,
+                  "zip" => $zip,
+                  "perm" => $perm,
+                  "code" => $code);
+  $data[] = $newsig;  // newsig is a separated variable for debugging purposes
+
+  // Encode to JSON again and write to file
+  $allsig = json_encode($data, JSON_PRETTY_PRINT);
+  file_put_contents($db, $allsig, LOCK_EX);
+  unset($allsig);
+  
+  // Send email asking for confirmation
+  $to      = $email;
+  $subject = "One step left to sign the open letter";
+  $message = "Please confirm $code";
+  $headers = "From: noreply@mehl.mx" . "\r\n" .
+      "Message-ID: confirmation-$code@fsfe.org" . "\r\n" .
+      "X-Mailer: PHP/" . phpversion();
+
+  mail($to, $subject, $message, $headers);
+}
+
+echo "<pre>";
+print_r($data);
+echo "</pre>";
+unset($data);
 ?>