diff --git a/website/queries/checkInput.php b/website/queries/checkInput.php
index d48e4e0..ceb110f 100644
--- a/website/queries/checkInput.php
+++ b/website/queries/checkInput.php
@@ -1,4 +1,10 @@
 <?php
+/**
+ * Function for checking inputfields
+ * @param variable $example Give name of the inputfield.
+ * @param string $example2 Give the name of the option.
+ * @return sets correct to false and gives value to error message if it doesn't pass the checks.
+ */
 function checkInputChoice($variable, $option){
     if (empty($_POST[$variable])) {
         $GLOBALS[$variable . "Err"] = "Verplicht!";
@@ -22,21 +28,21 @@ function checkInputChoice($variable, $option){
           case "email";
             validateEmail($variable);
             break;
-            
+
           default:
             break;
-
         }
     }
 }
 
+/* Checks for only letters and spaces. */
 function checkOnly($variable){
     if (!preg_match("/^[a-zA-Z ]*$/",$GLOBALS[$variable])) {
         $GLOBALS[$variable . "Err"] = "Alleen letters en spaties zijn toegestaan!";
         $correct = false;
     }
 }
-
+/* checks if username exist and if its longer than 6 characters. */
 function username($variable){
     if (strlen($GLOBALS[$variable]) < 6) {
         $GLOBALS[$variable . "Err"] = "Gebruikersnaam moet minstens 6 karakters bevatten";
@@ -47,6 +53,7 @@ function username($variable){
     }
 }
 
+/* checks if an input is longer that 8 characters. */
 function longerEigth($variable){
     if (strlen($GLOBALS[$variable]) < 8) {
         $GLOBALS[$variable . "Err"] = "Moet minstens 8 karakters bevatten";
@@ -54,6 +61,7 @@ function longerEigth($variable){
     }
 }
 
+/* checks if an input is a valid email. */
 function validateEmail($variable){
     if (!filter_var($GLOBALS[$variable], FILTER_VALIDATE_EMAIL)) {
         $GLOBALS[$variable . "Err"] = "Geldige email invullen!";
@@ -66,6 +74,7 @@ function validateEmail($variable){
     }
 }
 
+/* checks if two passwords matches. */
 function matchPassword(){
     if ($_POST["password"] != $_POST["confirmpassword"]) {
         $GLOBALS["confirmpasswordErr"] = "Wachtwoorden matchen niet";
@@ -86,6 +95,7 @@ function registerCheck(){
     }
 }
 
+/* removes weird characters of an input. */
 function test_input($data) {
     $data = trim($data);
     $data = stripslashes($data);