Script to add a page number marker

Hi all,

I'm trying to add folios to currently unnumbered pages using a pretty simple script like:

app.activeDocument.masterSpreads.item("A-Parent").textFrames.add({
    geometricBounds: ["62", "40", "63", "47"],
    contents: "?",
    itemLayer: "Layer 1",
    parentStory: {appliedParagraphStyle: ""}
})

This creates the box just fine, but I have no idea what to use for the "contents: "?" to insert a current page number marker. I'm not even sure how to look this up. Is it even possible?

Thanks for any help!

-Don