diff --git a/gnuplot/README.org b/gnuplot/README.org
index 2223ef0..66b52b4 100644
--- a/gnuplot/README.org
+++ b/gnuplot/README.org
@@ -3,7 +3,7 @@
   usage:
     gnuplot line.gp                       run line.gp script
     gnuplot -p line.gp                    run script and kepp figure open
-    gnuplot -e "file='data.dat'; column1=1; column2=2; format=''; out=''" line.gp
+    gnuplot -e "file='data.dat'; column1=1; column2=2; format='png'; out='line.png'" line.gp
                                           run script with altered variables
 #+end_src