How do I automatically add all columns to the Column Switcher in .jsl

[#1]

I'm very much a beginner with JSL, I'm still learning --

I have many files that I need to review with Graph Builder, and each has a different number of columns.  The only constant is that I know I want column 1 as the Overlay, column 2 in the X-axis, column 3 in the Y-axis, and all the rest of the columns in the Column Switcher.  I'd love to have a script that would open up all the Graph Builder windows for all the currently-open data tables with these settings, but I don't know how to do that.  This is the closest I've gotten:

Graph Builder(
	Size( 1900, 1200 ),
	Variables(
		X( :Column(2) ),
		Y( :Column(3) ),
		Overlay( :Column(1) )
	),
	Elements( Points( X, Y, Legend( 10 ) ), Line( X, Y, Legend( 11 ) ) ),
	Column Switcher( :Column(3) ),
	SendToReport(
		Dispatch(
			{},
			"",
			ScaleBox
		)
	)
);

The two things I need help with:  (1) figure out how to set the Column Switcher to automatically load up all the columns in the data table without asking me, and (2) wrap this script in a loop that iterates over all the open data tables.

Thanks in advance!

[#2]

Thanks to those here who helped, I feel like I didn't add much of my own here.  This is basically what I ended up with:

The goal was to have a script that would go through a folder full of text files one at a time, load it, and bring up a Graph Builder window with some settings pre-set, then when Graph Builder is closed, it automatically opens the next one.

The approach I used was to manage it with global variables:  "regFlist" is the list of files left to open, and "stopReg" is a flag that when turned on interrupts the process.

There are two scripts:  (1) reg_Next.jsl -- checks regFlist, and if it's empty, it asks for a folder to use; otherwise it loads the next file from the regFlist list (if regStop is not set), (2) reg_Stop.jsl -- simply empties regFlist and sets the regStop variable; used to stop the process early.

I'm a total beginner with .jsl, so I'm very open to any feedback/constructive-criticism.

reg_Next.jsl

//!

// use global variables (since hey, what could go wrong? ;) )
Names Default To Here( 0 );

// get path to self
selfPath = get default directory() || "/reg_Next.jsl";

// check to see if user has requested a stop
If( stopReg == 1 ,
	stopReg = 0;
	regFlist = {};
	Stop();
);

// initialize list of files to review if there aren't any in the list
If( Is Empty( regFlist ) | N Items( regFlist ) < 1,
	jmpDir = Pick Directory( "Select the jmp directory." );
	regFlist = Files In Directory( jmpDir );
);

// open data table and remove it from the regFlist
dt = Open( jmpDir || "/" || regFlist[1] );
regFlist = Remove( regFlist, 1 );

// set up for column switcher
colList = dt << get column names( string );
col1 = colList[1];
col2 = colList[2];
col3 = colList[3];
Remove From( colList, 1, 2 );

// open graph builder
gb = dt << Graph Builder(
	size( 800, 600 ),
	Variables( X( As Column( col2 ) ), Y( As Column( col3 ) ), Overlay( As Column( col1 ) ) ),
	Elements( Points( X, Y, Legend( 10 ) ), Line( X, Y, Legend( 11 ) ) )
);
cs = gb << Column Switcher( col3, colList );

// set up mechanism to re-run myself when graph builder is closed
If( N Items( regFlist ) == 0,
	gb << on close( Close( dt, nosave ) ),
	gb << on close(
		Close( dt, nosave );
		Open( selfPath, Run JSL( 1 ) );
	)
);

reg_Stop.jsl

//!
Names Default To Here( 0 );
regFlist = {};
stopReg = 1;