Adobe Acrobat Javascript Forms - Show/Hide layers in multiple pages

Question

I'm using javascript language to make a Adobe Acrobat Forms with layers. I have a problem with show/hide this layers when it is a multiple page document when it is a page it's working fine.

The idea is:

I have a PDF document with two pages. I have a combobox in the page 1. I have three layers in the page 2. When I choose an option of this combobox show or hide layers of the page 2.

The code is running of combobox with the event validate of the propierties:

var layers = this.getOCGs(0); 

if (event.value == "NAP") {
    layers[0].state = true;
    layers[1].state = false;
    layers[2].state = false;

}else if(event.value == "MOD"){

    layers[0].state = false;
    layers[1].state = true;
    layers[2].state = false;

}else if(event.value == "NIT"){

    layers[0].state = false;
    layers[1].state = false;
    layers[2].state = true;

}else{

    layers[0].state = false;
    layers[1].state = false;
    layers[2].state = false;
}

I see the debug console an show this message:

TypeError: layers is null

I do not understand why it's working fine when the document is only a page and it's not working fine when the document are two pages or more.

Please Could you help me?

Thanks!

Answer 1

That first line of code will return the layers on the first page. If you want to get the layers on the second page, use 1 as the parameter instead of 0.