I am facing a problem with the checkboxes on the spawned page.

Here is my code for the spawned page

var SpawnPage = this.getTemplate({cName: "table"});
  SpawnPage.spawn({nPage: this.numPages, bRename: true, bOverlay: false});
    this.getField("P" + (this.numPages - 1) + ".table.Name").setFocus();

The code for the checkbox looks like this:

var nDisplay = event.target.isBoxChecked(0) ? display.visible : display.hidden;
this.getField("P" + (this.numPages - 1) + ".table.Dropdown39").display = nDisplay;
this.getField("P" + (this.numPages - 1) + ".table.Text40").display = nDisplay;
this.getField("P" + (this.numPages - 1) + ".table.Text41").display = nDisplay;

Unfortunatelly it doesn't work. I have no idea how I should link the checkbox to the correct element on the spawned page...