Making a New Page in Indesign

I have seen how to create a new page in an existing document in InDesign.

make page at after page 1

the problem I have with that is that I have a document with three pages that are side by side in my layout.
I would like to keep all the pages side by side.
When I use the above statement, it makes a new page, but it inserts it on the next row of my page layout AND it pushes the other two pages (now page 3 and 4) to a third row in my page layout.

I have never manipulated the page layout window. Any guidance please.

David

I got it figured out…

if (pageWidth = 12.0) and (pageHeight = 17.63) then
tell document 1
tell spread 1
set allow page shuffle to false
make page at after page 1
end tell
end tell
end if