diff --git a/lib/member_functions.php b/lib/member_functions.php
index ff41a26b7f2380119f59adea7586430ff37a2043..f5f4d7be93954a1775fc12f1b574ef2642dc99da 100644
--- a/lib/member_functions.php
+++ b/lib/member_functions.php
@@ -41,14 +41,14 @@ function generateUid()
     while ($ok == false) {
 
         //generate random number between 00000 and 99999
-        $uid = sprintf("%06d", mt_rand(0, 99999));
+        $uid = sprintf("%05d", mt_rand(0, 99999));
 
-        // id return 1 for error (safe to take). 0 for sucess (taken) not safe
-        shell_exec("id ".$prefix.$uid, $output, $returnVal);
+        //id return 1 for error (safe to take). 0 for success (taken) not safe
+        exec("id ".$prefix.$uid, $output, $returnVal);
 
         //check the result of id
         if ($returnVal == 1) {
-            // We have a unused one!
+            // We have an unused one!
             $ok = true;
             $safeuid = $prefix.$uid;
         }