diff --git a/create_mass_primtux_users.sh b/create_mass_primtux_users.sh
index baa7720a3e9d7f8ec043f4a37240193a105171e3..2ec3517f9859b5952ee30c7990d3a66fc83956e7 100755
--- a/create_mass_primtux_users.sh
+++ b/create_mass_primtux_users.sh
@@ -19,20 +19,21 @@
 DIR=`dirname $0`
 
 usage(){
-    echo "Usage $0 users.txt"
+    echo "Usage $0 [users.txt]"
     echo "Reads a list of users and create them"
     echo "then run $DIR/create_primtux_user.sh on each of them with the apropriate level"
 }
 
-if [ -z "$1" ]
+in="users.txt"
+if [ ! -z "$1" ]
 then
-    usage
-    exit 1
+    in="$1"
 fi
+echo "Using input file $in"
 
-if [ ! -f "$1" ]
+if [ ! -f "$in" ]
 then
-    echo "$1 is not a file"
+    echo "$in is not a file"
     usage
     exit 1
 fi
@@ -77,7 +78,7 @@ do
     echo $uid >> uids.txt
     echo "Done creating $uid"
     OK="$OK $uid"
-done < $1
+done < $in
 echo "The following users where correctly created"
 echo -e "\t$OK"
 if [ ! -z $KO ]