diff --git a/php/api.php b/php/api.php
index 4c259cb..d9e8381 100755
--- a/php/api.php
+++ b/php/api.php
@@ -5,8 +5,15 @@
 # @copyright	2015 by Tobias Reich
 ###
 
-if (!empty($_POST['function'])||!empty($_GET['function'])) {
+# Define the called function
+if (isset($_POST['function']))		$fn = $_POST['function'];
+else if (isset($_GET['function']))	$fn = $_GET['function'];
+else								$fn = null;
 
+# Check if a function has been specified
+if (!empty($fn)) {
+
+	# Start the session and set the default timezone
 	session_start();
 	date_default_timezone_set('UTC');
 
@@ -15,6 +22,13 @@ if (!empty($_POST['function'])||!empty($_GET['function'])) {
 	require(__DIR__ . '/autoload.php');
 	require(__DIR__ . '/modules/misc.php');
 
+	# Validate parameters
+	if (isset($_POST['albumIDs'])&&preg_match('/^[0-9\,]{1,}$/', $_POST['albumIDs'])!==1)	exit('Error: Wrong parameter type for albumIDs!');
+	if (isset($_POST['photoIDs'])&&preg_match('/^[0-9\,]{1,}$/', $_POST['photoIDs'])!==1)	exit('Error: Wrong parameter type for photoIDs!');
+	if (isset($_POST['albumID'])&&preg_match('/^[0-9sfr]{1,}$/', $_POST['albumID'])!==1)	exit('Error: Wrong parameter type for albumID!');
+	if (isset($_POST['photoID'])&&preg_match('/^[0-9]{14}$/', $_POST['photoID'])!==1)		exit('Error: Wrong parameter type for photoID!');
+
+	# Check if a configuration exists
 	if (file_exists(LYCHEE_CONFIG_FILE)) require(LYCHEE_CONFIG_FILE);
 	else {
 
@@ -46,16 +60,7 @@ if (!empty($_POST['function'])||!empty($_GET['function'])) {
 	$plugins = explode(';', $settings['plugins']);
 	$plugins = new Plugins($plugins, $database, $settings);
 
-	# Validate parameters
-	if (isset($_POST['albumIDs'])&&preg_match('/^[0-9\,]{1,}$/', $_POST['albumIDs'])!==1)	exit('Error: Wrong parameter type for albumIDs!');
-	if (isset($_POST['photoIDs'])&&preg_match('/^[0-9\,]{1,}$/', $_POST['photoIDs'])!==1)	exit('Error: Wrong parameter type for photoIDs!');
-	if (isset($_POST['albumID'])&&preg_match('/^[0-9sfr]{1,}$/', $_POST['albumID'])!==1)	exit('Error: Wrong parameter type for albumID!');
-	if (isset($_POST['photoID'])&&preg_match('/^[0-9]{14}$/', $_POST['photoID'])!==1)		exit('Error: Wrong parameter type for photoID!');
-
-	# Function for switch statement
-	if (isset($_POST['function']))	$fn = $_POST['function'];
-	else							$fn = $_GET['function'];
-
+	# Check if user is logged
 	if ((isset($_SESSION['login'])&&$_SESSION['login']===true)&&
 		(isset($_SESSION['identifier'])&&$_SESSION['identifier']===$settings['identifier'])) {
 
@@ -85,8 +90,8 @@ if (!empty($_POST['function'])||!empty($_GET['function'])) {
 
 } else {
 
-	exit('Error: Called function not found!');
+	exit('Error: No API function specified!');
 
 }
 
-?>
+?>
\ No newline at end of file