I have a graph created by graph builder and a column in the data contains a constant value that I'd like to automatically add as a reference line to the graph. Adding the column to the plot axis gives me something (green vertical below) but it's not great looking, any better ideas?

Here is a simple example that draws a reference line based upon the value of row 1 from column Weight

Graph Builder(
Variables( X( :weight ), Y( :height ) ),
Elements( Points( X, Y, Legend( 6 ) ), Smoother( X, Y, Legend( 7 ) ) ),
SendToReport(
Dispatch( {}, {:weight}, ScaleBox,
{Add Ref Line( 95, "Solid", "Red", "", 1 )}
),
Dispatch( {}, "Graph Builder", FrameBox,
{Add Graphics Script(
2,
Description( "" ),
rp = Current Report();
rp[axis box( 1 )] << add ref line( :weight[1], "solid", red );
)}
)
)
);
I produced the complete JSL by right clicking on the graph and selecting Customize. Then clicking on the "+" and writing the simple script
rp=current report();
rp[axis box(1)] << add ref line(:weight[1],"solid",red)

After applying the little script, I went back to the red triangle in the graph, and saved the script to a script window.
I have a similar question, but I want to write new axis titles for X- and y-axis. I tried to use this script addition below and few other versions but nothing would override the axis titles just taken from Column Titles.
rp = Current Report();
rp[AxisBox( 1 )] << Set Title( "Conversion % at 160C" );
\\another version
Dispatch( {}, "Mean(BuOH Conversion Predicted_60hr, 160)", TextEditBox,
{Set Text( "Conversion % at 160C" )}),
Interactively run create your graph. Make the changes to the X and Y axis labels. Then go to the red triangle and select Save Script and save it to a Script Window. The script that will be displayed will show what you need to do to change the X and Y axis labels.