diff --git a/doc/xschem_man/graphs.html b/doc/xschem_man/graphs.html
index 4c1c2d71..37101587 100644
--- a/doc/xschem_man/graphs.html
+++ b/doc/xschem_man/graphs.html
@@ -261,6 +261,17 @@ The following syntax:

The graph dialog box has a Sweep textbox where you can write the
+ X-axis variable. By default xschem uses the first variable in the raw file for the X-axis, and this is the
+ sweep variable the simulation was done, so time for transients, frequency for AC sims, voltage or current sweep
+ for DC sims. Example below shows a cmos latch where a DC simulation has vbeen done sweeping the voltage generator
+ on the a input from 0 to 3V.
+ 
+ If v(a) v(z) is specified in the Sweep textbox (or a z) the z signal
+ will be plotted vs a and the a signal will be plotted vs z.
+ 
+