I am trying to change properties such as color/size/transparency of both markers and lines on overlaid graphs using scripts (tied to user inputs like check boxes and text boxes). Below is code I was playing with to try and figure how to manipulate the script, but not sure that I know what I am doing :-). If you know answers to questions in comment lines of the code or if you know a syntax reference exists for gb functions, please post...Thanks...
//Create table
dt = New Table("grphbldr.jmp", Add Rows(10),
       New Column("X", Numeric, Continuous, Set Values(1::10)),
       New Column("Y1", Numeric, Continuous, Formula(:X^2)),
       New Column("Y2", Numeric, Continuous, Formula(3*:X^2-100)),
);
gb = Graph Builder(
       Show Control Panel( 0 ),
       //Syntax to clear variables and new ones?
       //what is Position(1)?
       Variables( X( :X ), Y( :Y1 ), Y( :Y2, Position( 1 ) ) ),
       //information/syntax about Elements, Legend? 
       //Why doesn't a legend show for Y(2) points on graph?
       Elements(
              Points( X, Y( 1 ), Y( 2 ), Legend( 1 ), Jitter( 1 ) ),
              Line(
                     X,
                     Y( 1 ),
                     Y( 2 ),
                     Legend( 2 ),
                     //Info about Row order? 
                     //Draws lines through missing points?
                     Row order( 0 ),
                     Summary Statistic( "Mean" )
              )
       ),
       SendToReport(
       //what is "400"?
              Dispatch( {}, "400", ScaleBox, 
                     {
                     //change transparency of points. 
                     //Legend Model(1) for points. Properties(0) - for Y1, 
                     //and Properties(1) for Y2?
                     //How to set marker type and size for points?
                     Legend Model( 1 , Properties( 0, {Transparency( 0.6 )} ) ), 
                     Legend Model( 1 , Properties( 0, {Transparency( 0.4 )} ) ), 
                     //change transparency and line thickness of lines.
                     //Legend Model(2) for lines. Properties(0) - for Y1, 
                     //and Properties(1) for Y2?
                     Legend Model( 2 , Properties( 0, {Line Width(2), Transparency( 0.6 )} ) ), 
                     Legend Model( 2 , Properties( 1, {Line Width(5), Transparency( 0.4 )} ) ) 
                     
                     }
              )
       )
);